I dont think he designed the Apollo series? I think he bought the rights to the designs later on.
I dont think that they sell pre-programmed Apollo 1260 MACH chips on ebay do they? Yes for EPROM, yes for voltage regulator, yes for oscillator.
I doubt they can be reverse engineered. The chips almost certainly cannot have their current program read from them.
€25 each may not sound like much, but there are 3 of them on the A4060