If I remember correctly the 22 Lovell (a rimmed case) was also called the 22-3000. I believe I was taught that in 1966-67 at Gunsmithing College in Trinidad Colorado. Mr Prator was my instructor at that time.
The 22-250 was wildcatted from the 250-3000 cartridge. Perhaps that causes confusion in the names?
I guess until Remington made (and named) the 22-250 a commercial cartridge anyone could call it anything they wanted...
22-3000 ammunition (based on the rimmed case) is available today... https://www.buffaloarms.com/22-3000...aka-r-2-lovell-ammunition-box-of-20-amo223000
^^ There you go!