I got access to some new carbide bits and a Milwaukee with like 4 battery packs. As it slows down I swap out and charge the old pack. Don’t have access to a large enough air compressor. Agreed, it definitely isn’t glamorous work, but I did expect to be further along after the time I had invested. Can take pics when I get back to the shop maybe this weekend.
Use some trans fluid to help cut faster if need be. I used a Black and Decker drill my Grandpa gave me when I did my first attempt at porting a slant 6. The head flowed 175cfm when I tested it decades later 'I still have the head too' . Good luck.