Rolf-Dieter,
Maybe you can check with Metric Motors. A few years ago as I recall a full rebuild, top and bottom, was in the neighbourhood of $5 or 6 thousand. May have gone up a bit, but prices used to be quoted in their website. Add the cost of ahipping and you have your number.
I happen to have such an engine stand built specifically for our series engines, with even a tachometer.