Looks like you've done a nice job.
For a back block I would recommend the KAPP razor cut back block. Very nice.
Only one question though, how much did this lot cost you?
I have thought about building my own custom cocker. I always come back to the same thing though. Price.
You have obviously put a lot of love into that puppy, but its still a boxy right hand feed cocker, that no-one wants to pay more than £200 for. Ok if you are keeping it for ever but tough on the pocket for resale value.
I have just bought a 2002 Eclipse cocker, £400. Sweet as a nut and I couldn't have upgraded a normal cocker for that. Let alone the milling.
Suppose some things are about more than £.
Nice job though.