I was obsessed with those beautiful optional tailstocks built by Leinen that appear in the lathe parts catalog. An intense surveillance in ebay has given some partial results. The first attempt achieved this nice capstan-handle tailstock that admits the 25 mm 363E collets:
However, although the tailstock is in pretty good condition (just cosmetic issues) it is not appropiate to the Leinen LZ4SB dimensions. It shares the 130mm center height but the bed dimensions are not the same.
