http://www.ebay.co.uk/sch/minifux1/m.html - here's his ebay store. Fast postage and reasonable costs. There's no buy it now but auctions normally end close to starting bids. Exceptions are those coveted transistors like NKT275's which go for quite a lot. Try AC125, AC150 (Build a Fuzz Face yesterday with one in Q2 and I'm pretty chuffed) and ASX12.
Other options is to go with russian transistors.
http://stores.ebay.co.uk/elena8913?_trksid=p2047675.l2563 - this is the guy for them. Reasonable cost and gets you pretty good range of values. It's just loads of them so you need to know what you're looking for.
Chromesphere on youtube (
https://www.youtube.com/user/chromespherecom) did his videos on Germaniums and he discusses couple of good Russians there. Also, this database:
http://transistor-spravochnik.ru/ is useful for transistors. It's in Russian but pretty straightforward. Lists all the reelvant parameters and also gives you analogue transistors of other makes, for example
http://transistor-spravochnik.ru/description/gt402i/38467 - you can see that it is listed as a repalcement for many European types, including AC128
Hope this helps!