I'm a month or more later. I've tidied up everything, electrics, fixed some compression woes and built a water pump for cooling. mostly just procrastinating the inevitable, ie, starting it. the main issue I believe now is probably gas flow, I have no real control over how much. someone mentioned...
ok, I'm about 90% into Jerry H's demand valve. there are some design issues that don't work. I hope I have the right needle and seat.
I machined it all and put it together, then realised the needle sits way too high, to the point that when I sit the diaphragm on, then the valve is pushed in and...
scan the drawings or get them scanned, get them touched up, and bung them on the internet with a 10 dollar download fee. build a steam engine for the compressor.