"On this 92 B230FT there is no oil to air cooler just an oil to water cooler"

Yes, I know how the 1992 and on turbos are equipped for oil cooling.

"run the early 740 oil to air cooler lines (scavenged from the junkyard)."

The steel lines fit to the oil cooler adapter for the air/oil heat exchanger. The oil cooler adapter has a thermostat in it. This method won't work because you would only filter oil when the 95ºC oil theermostat is open

"How effective is the oil/water cooler?"

Very efective.

"Would I benefit from removing the factory oil/water cooler for an after market oil/air cooler?"

No.

"but the oil/water cooler can be problematic as I found."

No, not problematic. It was a consequence of lack of maintenance.

"Now that I think about it, my 760 has the oil/air cooler but I am hesitant to try and remove them for a test fit since the 760 is in "full service.""

It won't fit anyway. The 1992 and later turbo cars use a different intercooler and radiator. There isn't room for the oil/air heat exchanger alongside the radiator. It would also interfere with the mid level intercooler outlet.

"This has been a lot more effort than I intended and I should have just bought the amsoil unit that comes with all the fittings and hose. After I factor all the time and trials, I would have been better off going with the more expensive kit! At least if I document what I do it'll save the next guy the hassle and that is what this board is all about - guess it was my turn."

If you are going to proceed, you might want to look at installing the actual oil/water heat exchanger directly on the block where it is on the 1986 and earlier 700 series turbos. You could then mount the PermaCool uniut directly on top of it and bring the hoses forward.