I think your friend probably meant Model Fixings. **LINK**
They do lots of bits and pieces. I have bought nuts, screws and drills from them. Highly recommended.
Can't help with your other queries though.
Bryan
Hi Paul
I've just joined the forum and read your post. This is probably too late but I have an ABS cowl for the Aichi which I could let you have. It is 115mm dia at the rear face and the front opening is 58mm, length is75mm.
Regards Bryan Lea