I have an MG614 that's in mint physical condition (retail packaging) but has a tape playback speed fault.
I replaced the mechablock which fixed it but the fault came back shortly afterwards.
The replacement block came from a gx52 for £15, so they can still be had for cheap.
Could be an easy fix for someone, or could just be useful as a mixer.
Wouldn't be looking much to get rid of it.
Sorry if this is an uncool highjack.