Here's a pretty little table with all the details:
Year | Beer | Style | Price | size | package | FG | OG | Colour | ABV | attenuation |
1948 | Double Diamond Pale Ale | Pale Ale | 13d | half pint | bottled | 1009.4 | 1045.2 | 18 B | 4.48 | 79.20% |
1950 | Sparkling Ale | Pale Ale | pint | bottled | 1007 | 1029.7 | 24 B | 2.84 | 76.43% | |
1950 | Special Stout | Stout | pint | bottled | 1011.7 | 1035.9 | 1 + 14 | 3.03 | 67.41% | |
1950 | Nut Brown Ale | Brown Ale | pint | bottled | 1009.5 | 1029 | 40 + 9 | 2.44 | 67.24% | |
1950 | Burton Pale Ale (Double Diamond) | Pale Ale | pint | bottled | 1011.2 | 1045.2 | 21 B | 4.25 | 75.22% | |
1950 | Arctic Ale No. 1 | Barley Wine | pint | bottled | 1020.8 | 1079.9 | 40 + 16 | 7.39 | 73.97% | |
1950 | John Bull Ale | Pale Ale | pint | bottled | 1012.2 | 1042.5 | 40 + 13 | 3.79 | 71.29% | |
1950 | Allsopp Nut Brown Ale | Brown Ale | 15d | pint | bottled | 1007.7 | 1029.9 | 7.5 + 40 | 2.78 | 74.25% |
1950 | Sparkling Ale | Pale Ale | 15d | pint | bottled | 1007.4 | 1029.7 | 25 B | 2.79 | 75.08% |
1950 | Allsopp Special Stout | Stout | 18d | pint | bottled | 1010.4 | 1034.4 | 1 + 40 | 3.00 | 69.77% |
1950 | Double Diamond | Pale Ale | half pint | bottled | 1012.3 | 1047.9 | 19.5 B | 4.45 | 74.32% | |
1950 | Sparkling Ale | Pale Ale | 9d | half pint | bottled | 1007.7 | 1033.3 | 22 B | 3.20 | 76.88% |
1950 | Double Diamond | Pale Ale | 14.5d | pint | bottled | 1010.9 | 1048.3 | 21 B | 4.68 | 77.43% |
1950 | Special Stout | Stout | 12d | pint | bottled | 1014.9 | 1038.2 | 1 + 14 | 2.91 | 60.99% |
1950 | Arctic Ale | Barley Wine | 18d | nip | bottled | 1020.1 | 1079.8 | 18 + 40 | 7.46 | 74.81% |
1950 | Nut Brown Ale | Brown Ale | 9d | half pint | bottled | 1008.6 | 1032.3 | 40 + 9 | 2.96 | 73.37% |
1951 | Special Stout | Stout | 12d | half pint | bottled | 1013.4 | 1038.3 | 1 + 14 | 3.11 | 65.01% |
1951 | Nut Brown Ale | Brown Ale | 9d | half pint | bottled | 1007.7 | 1032.6 | 40 + 8 | 3.11 | 76.38% |
1951 | Double Diamond | Pale Ale | 14.5d | half pint | bottled | 1010 | 1047.7 | 25 | 4.71 | 79.04% |
1951 | Sparkling Ale | Pale Ale | 9d | pint | bottled | 1008 | 1032.1 | 25.5 | 3.01 | 75.08% |
1951 | Allsopp Special Stout | Stout | 12d | half pint | bottled | 1011.9 | 1037.8 | 3.24 | 68.52% | |
1951 | Arctic Ale | Barley Wine | 17.5d | nip | bottled | 1019.1 | 1078.1 | 7.37 | 75.54% | |
1951 | Special Stout | Stout | 14.5d | half pint | bottled | 1015.3 | 1037.1 | 1 + 16 | 2.72 | 58.76% |
1951 | Nut Brown Ale | Brown Ale | 9.5d | half pint | bottled | 1008.3 | 1031.9 | 17 + 40 | 2.95 | 73.98% |
1951 | Sparkling Ale | Pale Ale | 9d | half pint | bottled | 1007.6 | 1032.6 | 21 | 3.12 | 76.69% |
1952 | Arctic Ale | Barley Wine | 18d | nip | bottled | 1020.2 | 1080.3 | 21 + 40 | 7.51 | 74.84% |
1952 | Nut Brown Ale | Brown Ale | 9.5d | half pint | bottled | 1011.7 | 1030.9 | 11 + 40 | 2.40 | 62.14% |
1952 | Special Stout | Stout | 23d | pint | bottled | 1011.5 | 1037.9 | 1 + 11.5 | 3.30 | 69.66% |
1952 | Coronet Pale Ale | Pale Ale | 11d | half pint | bottled | 1008.6 | 1035.6 | 22 B | 3.37 | 75.84% |
1953 | Arctic Ale | Barley Wine | 18d | nip | bottled | 1018 | 1079 | 18 + 40 | 7.63 | 77.22% |
1953 | Double Diamond | Pale Ale | 11d | nip | bottled | 1009.7 | 1048.7 | 23.5 | 4.88 | 80.08% |
1953 | Allsopp Special Stout | Stout | 10d | nip | bottled | 1013.4 | 1038.1 | 1 + 11 | 3.09 | 64.83% |
1954 | Sparkling Ale | Pale Ale | 12d | half pint | bottled | 1008.5 | 1030.5 | 26 | 2.75 | 72.13% |
1954 | Nut Brown Ale | Brown Ale | 9.5d | half pint | bottled | 1009.7 | 1030.7 | 11 + 40 | 2.63 | 68.40% |
1954 | John Bull Ale | Pale Ale | 15d | half pint | bottled | 1014.8 | 1048.1 | 115 | 4.16 | 69.23% |
1955 | Double Brown Ale | Brown Ale | 12.5d | half pint | bottled | 1012.6 | 1047.8 | 45 | 4.40 | 73.64% |
1955 | Nut Brown Ale | Brown Ale | 11d | half pint | bottled | 1011.2 | 1033.6 | 105 | 2.80 | 66.67% |
1955 | Double Diamond | Pale Ale | 16d | half pint | bottled | 1012.7 | 1048.5 | 19 | 4.47 | 73.81% |
1956 | Nut Brown Ale | Brown Ale | 10d | half pint | bottled | 1012.3 | 1032.2 | 90 | 2.49 | 61.80% |
1956 | Light Ale | Pale Ale | 10d | half pint | bottled | 1010.5 | 1031 | 22 | 2.56 | 66.13% |
1956 | Special Stout | Stout | 13d | half pint | bottled | 1014.9 | 1038.1 | 250 | 2.90 | 60.89% |
1956 | Sweet Stout (lactose present) | Stout | 14d | half pint | bottled | 1016.5 | 1038.5 | 250 | 2.75 | 57.14% |
1956 | Double Diamond | Pale Ale | 17d | half pint | bottled | 1012.7 | 1048.3 | 20 | 4.45 | 73.71% |
1956 | Double Diamond | Pale Ale | 17d | half pint | bottled | 1014.1 | 1047.9 | 19 | 4.23 | 70.56% |
1956 | Arctic Barley Wine | Barley Wine | 18d | nip | bottled | 1019.7 | 1077.1 | 105 | 7.17 | 74.45% |
1959 | Double Diamond | Pale Ale | 16d | half pint | bottled | 1011.9 | 1047.5 | 20 | 4.45 | 74.95% |
1959 | "Dry Club" Stout | Stout | 13d | half pint | bottled | 1013.2 | 1038.7 | 240 | 3.19 | 65.89% |
1959 | Allsopp's Sweet Stout | Stout | 14d | half pint | bottled | 1015.4 | 1037.8 | 275 | 2.80 | 59.26% |
1959 | Light Ale | Pale Ale | 10d | half pint | bottled | 1009.8 | 1031.5 | 20 | 2.71 | 68.89% |
1959 | Benskins Colne Spring Ale | Barley Wine | 23.5d | half pint | bottled | 1009.3 | 1092.8 | 80 | 10.44 | 89.98% |
Source: Whitbread Gravity Book |
As you can see, bottled Double Diamond was around 1048 (good guess, Zythophile).
I was pleased to find Coronet, another beer mentioned by Campbell. It has a fairly puny OG of just 1035.6. Arctic Ale was another I'd hoped to discover. I wasn't disappointed. There are several entries for it. The OG was a very respectable 1080 or so and, because it was quite highly attenuated for a strong beer, it had a very respectable ABV of about 7.5%.
Right at the end you'll see the legendary Benskins Colne Spring Ale, which is also mentioned by Campbell. It has an apparent degree of attenuation of nearly 90%. Very impressive for such a big beer, leaving it over 10% ABV.
My apologies for missing these beers first time through.