It will not play anything smaller than 12".

On LPs and 12" singles, it'll start to play with no problem then about 30 seconds into the song it'll start skipping, this is the same with every record.

Is this something simple that I can sort out, or do I need to attempt to find a good yet reasonably priced repairman?

Incidentally, if anybody knows of a reputable but cheap repairman in the north London area, please let me know. I have a Rega Planar 3 that needs looking at too.