The Vox UL 460
Amps are registered in two sections: (1) by serial number if known; and (2) lower down the page, serial numbers unknown.
Serial numbers begin at 4000 or 4001. Note that serial numbers are not a reliable guide to relative date, ie. amp no. 4020 could easily be later than amp. no. 4030.
Although it is difficult to be sure, somewhere in the region of 50-100 UL460s were probably produced.
SERIAL NUMBERS KNOWN
SERIAL NUMBERS UNKNOWN
A bit rough round the edges, but perfectly serviceable. Further images are available here.