Value of old UK registration plates?

I have a chance to buy a pair of UK registration plates that came off the front mudguard of a 1972 Norton Commando Interpol. I have no idea of the fair value. Neither does the seller. Any idea what the going rate is?

No value, unless you have the V5 ie UK title and live in UK, other than the cost of the decal.

The bike is still on the DVLA registry, the value will be in the frame and registration number together (the V5). As things to hang on the garage wall probably no more than 10 quid if that. Unless of course they have some provable provenance that Steve McQueen rode the bike with those number plates!