The oddest being that Bismarck liked Russian Stout. Especially as the advert is from just after WW I, when there was still considerable anti- German feeling.
Matured at least a year in bottle
Its rich, creamy flavour, its warming goodness, distinguish it from any other stout you have tried. This stout was originally brewed nearly 150 years ago for export to Russia, to meet the demand of the old Russian aristocracy for a really choice, full-bodied stout. It continued to be exported up to the time of the War.
The finest winter drink
BARCLAY, PERKINS & Co.,
SOUTHWARK, LONDON, S.E.
Barclay's Southwarke Old Ale will also repay acquaintance."
Pall Mall Gazette - Monday 23 October 1922, page 5.
Another claim is that it was matured for at least a year after bottling. That's on top of the time spent maturing in a vat, which I think wqas two years. So you were looking at a beer that was probably at least three years old by the time it was drunk.
"Nearly 150 years" putd the date of the first brew probably in the early 1780s. Which is usually about the date claimed. Not sure how correct that is. I've learned not to trust brewery marketing materials. I've often found the claims - specifically ones about dates - to be inaccurate.