Its my understanding that Otari MTR-10/12 decks can be made to run at
3-3/4by moving some jumpers. I havent done this yet, but I plan to at some
point.
The Technics RS-1500 decks will do 3-3/4 and they have a switch able
headstack that will play/rec half track tapes and play only 1/4" track
consumer type tapes.
These are great decks, they have an Iso-loop tape transport system and
there very reliable. Not the easiest to use or setup however.
Akai made one machine that would hold 10reels and would play at 1-7/8these
are very hard to find.
Im not sure the Sony APR-5003 decks will do 3-3/4but I would imagine
they would, some studer decks will, and most Sony consumer types will.