Figure the "built-in" collet-closer taper only needs one or several of:
- A bushing that extends forward very little, but adapts to some more common collet. 3C? 5C? Pre-threaded tubes are available. You can make a "handwheel" drawtube closer very easily.
- A few "stubs" to fit the taper much as if it were Morse or jarno. These can be held-in with a simple draw bar (rod), not tube. ONTO such "tails" you can mount lots of things. Small flat-back chucks, drill chucks, etc.
His machine is pretty modern - it may use a standard morse taper in the tailstock. Mine did not, I simply made a new tailstock ram to fix that, and also
undo the wear on the underside of the non-split tailstock.
His spindle likewise probably does not use the smaller collet. The older lathes will take a suitably modified 3C directly in the spindle. The keyway in the collet
needs to be lengthened by about 1/8 inch. A carbide end mill is needed for this, the collets are pretty hard. Draw bar as you say can be hand made, but
a thrust bearing is a must. Again easy to make from stock parts.
If I had to move to smaller quarters, that would be the one lathe I would keep.
The drawbar is as mentioned home-made. It did not work well at all without the thrust bearing: