I didn’t have any collet for the levin yet but I just bough 12 assorted collets. Only 3 fit to the non-Levin drawbar. Now I know for sure they are different.I have an 8mm Derbyshire, WW-pattern lathe and in my experience, it's a bit of a crap shoot as to whether collets from other makers fit or not. The length of the collet, the size of the keyway, and the thread pitch and tolerances of the threads all factor into whether or not they will fit. Some collets from other makers fit just fine and others don't. Conversely, I have one of those little after-market accessories to hold a collet in the tailstock and none of my genuine Derbyshire collets fit it, but collets from other makers usually do. Do your Levin collets fit your Boley lathe?