Your cartridge is the most important component in analog chain, if you want the most noticeable upgrade in sound quality just change your cartridge. And don’t believe the hype (MC is not better than proper MM).
@chakster Of course you would say that because you peddle cartridges on eBay etc after recommendng them on this forum. You have a vested interest in that false argument.
The vintage moving magnets you recommend are unobtainable new and in most instances because the suspensions are very old, they are unlikely to be operating correctly as designed.
Best to buy the best turntable & arm he can afford and a starter cartridge.
There are plenty of good starter cartridges available new from Audiotechnica, Grado, Nagaoka, Ortofon etc.