One of the first things I made for both my Gingery lathe and my Craftsman 12" was a quick change tool post and a bunch of holders.
The Drummond type toolpost and holders are possible to make entirely on a lathe, without a milling machine. The post is a 1.25" dia (or similar convenient metric size) piece of cold rolled rod, drilled through axially to take a fastening bolt to attach to your slide.
The holders can be made via either a 4 jaw chuck or a faceplate. The tool holder's tool slot can be made using the toolpost itself by holding a milling cutter (slot drill) in the headstock, and milling the toolholder while clamped to the toolpost.
Here's a blast from the past thread I did when I first started equipping the Craftsman. BTW the same toolholders fit both the Gingery and Craftsman because I standardized on a 1.25" post.
I've never regretted making these! Thread here:
https://www.madmodder.net/index.php/topic,8415.0.htmlBelow: The toolpost mounted with a tool holder, and a bunch of blanks to be made into more holders to fit.