Unless you're going to go into commercial scale production it simply wouldn't be worth the effort. The 9010s are still available even if expensive. I keep three and I could have saved a lot more of them if I'm only known :-( If you were going to produce them commercially you'd also need to produce the various pods since those are also getting very hard to find (read $$$!) OTOH, if you were willing to redesign the circuits with modern ICs you could simplify it and reduce the chip count and costs dramatically. And replace that goofy mag tape with something a lot better!
The 9010s are a hell of a machine! I can see why they're steadily going UP in value. You can't say that very often for test equipment!
PS just thinking about it. If it were me, I'd reverse engineer the 9010 probe and try to build replacement ones. Those are almost impossible to find anymore. I think the last one that I saw for sale was listed at $800!!! And they're probably rather simple inside.