Hi Chris.
The CAT is looking really good, 'well jel' as they say!!
I'm doing a restoration project on my CAT 2000 EC too. But I can't find the alloy transmission housing anywhere!
Did you manage to get a shell for it? I've just ordered a new shell, undertray and wing off eBay - "teambluegroove" is the seller and I believe he's got some stock in. I can't vouch for the quality yet as I'm still waiting on the delivery (from Canada) but for £25 including delivery, I couldn't say no.
Would love to see some more pics of yours if you've made some more progress on it.
I'll post some pics up of mine when I get my Fibre-Lyte parts in the post.
Cheers,
Andy