I though I've already posted in this thread, but the best 42mm camera with spot metering or other metering paradigm and layout is the Canon F1n and F1N are which have excellent interchangeable focusing screens in three different metering patterns, including six spot patterns and layouts for a total of 32 choices
I've never had a FD spot screen, preferring stand alone meters, but the Canon FD system F1's are also easily adaptable to M42 lenses and I use Pentax lenses regularly on my F1's.
Cheers.