Assuming that the registration number is British (as is likely), then a registration date in December 1935 is correct. As Christine correctly points out, however, the actual manufacturer may not necessarily be British as many designs were registered by agents for overseas manufacturers.
Unfortunately, Reg. No. 808473 does not appear in 'The Blue Book' (Glass Association; registration numbers 1908-1945), but some registrations are not listed because they were listed (erroneously or for some other reason) under a class other than glass (pottery, for example).
An interesting item nonetheless.
Fred.