[GITERDUN]

Stanger,
The white machines had a Morse #4 taper in the lathe spindle and a Morse #3 in the tailstock. They also had a Morse # 3 in the mill spindle. They came with 2 drawbars, one for the lathe spindle and one for the mill with 3/8-16 threads. For an all purpose collet set, I would search E-Bay for a set of Morse #3 collets and a Morse #4 to Morse #3 reducer bushing. Then you would have a set capable of use in both lathe and mill. Most Morse collets have the 3/8-16 threads, but ask first, as there are some metric ones out there. Another alternative is to look for an ER-40 collet chuck and collet set with the Morse #3 taper on the chuck, then your chuck remains in the spindle and you simply change out the ER 40 collets of different sizes. It's a faster method, but a bit more pricey.

I would go with the ER 40 sets- they are faster and a lot less hassle than always loosening and tightening the drawbar to change out MT 3 collets.
Here is a link to a set on E-bay
15 PC ER40 Spring Collet Set Collets MT3 Chuck New | eBay