I wasn't going to list manufacturers for fear of advertising, but i probably know of more than most, so i'll mention everyone but ourselves.
Tikka stocks are available from:
Robertson ( via Jackson Rifles if you want it quick,) tactical and sporter types
KKC ( also via Pete J) laminated wood, quite futuristik
Manners, T4 tactical type
McMillan, couple of types inletted for T3
PSE Composites, Edi is working on a Sporter varmint for the T3, a E5 ( sort of a A5 copy) should follow, and as soon as the tikka importer delivers my new T3 Sporter,(have you guys seen that by the way?) with the copy of the master sporter stock, its some bodyfiller here and there and then off to Edi as a prototype to form the mold from,
Wild Dog, have a varmint and a sporter stock, look good, got some on shelf for builds.
chassis systems
There is a company in austria making what looks like a TRG folder, but its wood bolted to alloy and not composite and a bit agricultural. ( foldingstock.net)
I saw a new one on the hide from the USA that was basicaly a TRG type stock for the T3 made by KRG, guy who used to work for Magpull
I aren't sure if Mcree does one. he might
PDC Custom does one also.
There are also a half dozen wooden and laminated wood stock manufacturers dotted around europe who are capable of making a stock for the T3, at least 2 of those are in the UK.
not sure if i missed any, might be a couple more.
regards Pete