If I told you all that I know about this guy I would probably find myself in court!
However I can say that the last two engines from this sorce that I have investigated have had major problems ( 1/ chrome rings in chrome cylinders destoying the engine inside 50 hours 2/ Bent crankshaft instaled at overhaul)
Those are just two that I can positivley back up with hard evidence.
I have never had any dealings with Eisenburg however his reputation within the business is good, Nickelson McClarren are also building a good reputation but have not been in business long.