Thanks!
This looks like something that could work for me!
In the meantime, another option that I didn't consider is to find the socket that is inside the hook attechment of the probes and solder them onto wires. Unless they are similarly obtainable as the ground lead clip.
That's a much easier thing! Most scope probes have tips that are around 0.5, 0.8, or 1mm diameter. (0.5mm is usually an optional tip, the default is usually 0.8 or 1mm.) The Rigol probes I have are 1mm thick at the base and step down to about 0.75mm. My Testec probes are 0.8mm diameter.
Anyhow, what you want is the female contacts for D-sub type connectors. Standard D-sub pins (size 20) are 1.02mm diameter, while D-sub HD pins (size 22) are 0.76mm diameter. You can get them as open barrel crimp contacts, machined closed-barrel crimp contacts, solder cup (for size 20), etc. Ordinary female contacts (stamped or "economy" machined) are essentially split cylinders that spread when a pin is inserted. By applying heat shrink tubing to them after attaching the wire, you not only insulate it, but also provide additional tension on the contact. (There are also more expensive machined sockets that use internal contact baskets. I do not recommend these for this purpose, as you can't reinforce the contact tension, and they cost a lot more anyway.)
I have been making myself various test leads using stamped crimp D-sub HD females, as they have proven to be much more resilient in the long term, and work great on standard (0.64mm) square pins, which is my primary use for them. A $20 AliExpress D-sub crimper (such as SN-01B/-02B D-Sub crimper or other small contact crimper like an IWS-3221) will do the job nicely.
For the machined ones, you can either solder into them, or use an indent crimper (also available on Ali for ~$35).
I've attached a few pix of various contacts that would work. The key is the split-cylinder design that looks kinda like a duck and puts all the contact force right up front, so it'll work even if your probe tip tapers down. I've also added pix showing what a size 22 (HD) female contact looks like when pushed onto the Testec and Rigol probe tips. Even after being slightly overexpanded onto the Rigol, it still holds tight on the Testec.