Wilwood or aftermarket Master cylinder that works with kelsey Hayes Calipers?

An MC leaking down the firewall must be common since I don't think I've seen an A-body without rust below the MC (glycol removes paint). Often, it is spillage from the reservoir cap, or a sloppy mechanic long ago. When a manual MC piston leaks, you get fluid and rust in the cabin. A 7/8"D bore would work for manual brakes. The pedal might be "too easy" w/ a booster, but I recall the factory used the same MC bore for manual and power in those years. I recall someone recently posted about a problem with the Wilwood MC. Cheaper to use a factory 2-bolt w/ adapter plate (many posts, Dr. Diff sells kit), though Wilwood adds bling.