Since I got the DMM7510, well I am about to sell this one
https://www.eevblog.com/forum/repair/this-keithley-2001-need-to-be-saved!/unfortunately the main repair is already done by me.
What you could do is the upgrading phase (I have already all the components just not have the time) as well as the calibration.
You are absolutely right, the K2001 is THE best meter to learn and gets the hands dirty with metrology.I am sure you know you can attach a nanovoltmeter board... oh mine has the scanner board included.
That said, it will be not cheap, especially if I need to ship it in AUS.
I am still thinking about a price point.