Right, i have a cunning plan....
Would it be possible to remove the wood grip bit on a thompson, leaving just the Barrel and then forming a PPSh barrel to "cover" it. This would leave you with a thompson, with a ppsh barrel bit. I know it dosnt look exactly the same, but i presume if you can make a PPSh looking barrel bit, the i reckon you could make the stock and then BAM! PPSh.
Just an idea i had...
unless you'v got a thompson you dont mind carving up, wouldent it be easier to just buy a ppsh,or sell the thompson to fund the ppsh.other than that you could make one that way with a bit off clever sculpting,if you decide to go ahead be sure and post it up as a build thread.it would have the advantage of a verry well tried and trusted set of runnung gear and a drum mag that works well,ive heard that there are problems with some of the ppsh drum mags not feeding to well.best of luck.
armoury
m1a1 Thompson,sten mk2,mp40,stg44,sterling,mk2 bren gun,lee Enfield no4 mk1,Mauser Kar98, Walther ppk,smith and Weston m10 and Mauser m712
Give me a big enough hammer and a place to stand and I could fix the world.
i'll kill a man in a fair fight or if i think he's going to start a fair fight or over a woman or.......
a problem shared is a problem halved ,but an advantage shared is no advantage at all
if a job's not worth doing then its certainly not worth doing well
I was kinda hoping someone else might take on this insane idea of mine 
you could just buy a PPSH which i think, is quite expensive so this could be seen as a cheaper alternative...
im not sure
The motor in the thompson pistol grip will make this conversion improbable if not impossible. If you really do want to make your own PPSH, it would be better to convert in M14, like i did right before HP released their wonderful PPSH.
Yeah it was just a crazy idea so it dosnt matter that much, thanks for the heads up 
Indeed. With the amount of work involved, it might be easier (and cheaper) to start from scratch with an M14 GB/motor.
Yes as said you use an M14 as I have also done before China made them.
The ST PPSH only costs £205 posted to the UK with tax etc so only about £55 more than you can buy a cheapest option new M1A1 for.
The Thompson is not the way to do it.
I bought my M14 gearbox from the USA and built all the other parts stock, hop, receiver etc and converted a real drum.
http://www.youtube.com/watch?v=pl_ol9OvuII
http://www.youtube.com/watch?v=MbLqtSLmYBE
Free speech is expensive these days!
