I bought one of those (or similar) on eBay when I had the guitar shop
and occasionally worked on guitar amps. It still worked great although
it probably was out of calibration. Dual probes too. I lent it to a
guy who was doing some troubleshooting and that's the last I ever saw of
it. Can't even locate him anymore.
I loaned mine to a buddy about 15 years ago. He still has it. Have not
needed it.