bullpuppy wrote:...What would a run of the mill factory one fetch?
Depends very much on the location. At the origin in Germany a "Gitarrenlaute" of this condition would not fetch more than 100€ probably even (much?) less. Don't know the price level in other locations. Last year I was lucky to find a luthier made one at the bay in original condition, label and dust bunny inside and without cracks from 1928 for about 80€ which was quite a good buy but not exceptional. But prices might have gone up a bit meanwhile?!
As the name "Gitarrenlaute" indicates she is tuned like a modern CG. Gut or steel strings have been originally used with these instruments and recent sets are available with Nylon resp. steel strings from Pyramis and Thomastik for instance! Mine is strung with wound Nylon trebles from Savarez which seems to be good compromise.
Besides cracks in the bowl and/or the top a steep neck angle is the most common problem with these guitar-lutes, which causes a high action and makes them quite uncomfortable to play. Another thing to mention is the design of the fingerboard. Some are flat with normal fret wires and some are scalloped with the fret wires hardly protruding. The latter needs at least some time of familiarization.