I have a pair of straplocks on the fretless as shown in the following Ebay link:
http://www.ebay.co.uk/itm/STRAP-LOCK-NEW-GUITAR-OR-BASS-SUPER-SAFE-LOCK-GOLD-/361450242721?hash=item54281d02a1:g:PRgAAOSwQTVWBxW1
Yes, they are gold!
Last night the central nut came loose and fell off as did the large washer beneath which sits on top of the strap.
We found the nut no bother, but there is no sign of the washer.
If anyone has a suitable washer (or complete assembly) that they don't want/need, please let me know & we'll come to some arrangement.
G.