I'm perplexed about a couple of things as I learn more about what I acquired.
Surpmil's note seems to suggest the U.I.C. engraved on my Mk. 2/1 scope signifies Unicam Instruments Cambridge, but Peter Laidler's book Telescope Sighting No. 32 states on page 20:"Vickers Instrument Company, whose telescopes are marked with the logo U.I.C., were invited to ..." [Note it's clearly a "U" and not "V" in Peter's book since he uses the U.I.C. identification in several places.]Peter's chart of serial numbers ranges on page 32 lists "Vickers U.I. Co." as producing both Mk. 1 and Mk. 2/1 scopes.
Was Unicam a subsidiary of Vickers?
Back to page 20, again referring to the 2/1, Peter states:"Those manufactured by Vickers with the serial numbers in the 0-1000 range carry the part number OS1400GA and are very rare and highly prized by collectors."His serial numbers chart on page 32 lists:"Manufacturer: Vickers U.I. Co.My scope, as shown in the photos in my original post above, is marked:
From: 0 To: 1000
Mark: 2/1
Total: 1000
Remarks: Identified by figures OS 1400 GA"TEL. STG. NO 32, Mk. 2.Although my serial number (21) falls within the Vickers range (and none of the other manufacturers' ranges in Peter's chart), it has the 1650A nomenclature rather than the 1400 GA described in Peter's book.
U.I.C. O.S. 1650A.
No 21
Hence my confusion. It would seem I've got a Vickers manufactured Mk. 2/1 but the part number doesn't match what I would expect from the chart. Could it be I've got such an early tube the Mk. 2 part number was engraved but the later (?) part number was not added in place of the 1650A?
Am I missing something?