It's probably not economical to repair a VCR. (Parts would be extremely hard to come by and probably expensive as well).
Up until recently, Argos seemed to be about the last High Street retailer to sell VCRs but I've just checked their catalogue and they no longer sell them.
If you only want to use the device as a player (rather than to record), Maplins sell a device which can play VHS videos and send the output to either a TV set (by a Scart lead, in the usual way) or to a computer (for converting to a digital format and then, if required, for burning to DVD):
http://www.maplin.co....o-pc-convertor-508227
However you'd have to order online as there's no stock in their Glasgow stores.
Alternatively the British Heart Foundation will sell you a secondhand VCR, tested and warrantied, from one of their Furniture & Electrical stores at either
22 Stockwell Street, Glasgow, G1 4RT (0844 248 9135)
or
467 Dumbarton Road, Glasgow, G11 6EJ (0844 499 4151)
BHF's prices seem to vary between their stores. Down here in East Anglia, their Thetford shop usually sells them for a tenner, whereas their Ipswich shop sells them for around £20.
If you're determined to try a repair, this might help:
http://www.cgelect.co.uk/
Chris