HIATT 1960 marked 'MET POLICE', any value ?

I have a set of HIATT 1960 cuffs marked 'MET POLICE' in addition to the usual markings of maker, model, number and 'british made'. I think the cuffs are the 'long bow' type, from looking at the gallery on this forum, but not the heavy, as the rivet heads are flush.

I am currently listing the item on ebay if anyone cares to have a look, but I was wondering if anyone could tell me if the 'MET POLICE' markings add value, or are they relatively common.

Nige.

The item listing: http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 3950460931