Oedipus wrote:

HMV serial numbers are a bit of a minefield, as the system of numbering changed fairly frequently. The system introduced in 1930 (for all models, including the 101) had 10 digits, starting with the model number, and with '0's in the middle to allow for succession. This system carried on into the early 1930s (probably until 1934), although the 102 has 9 digits rather than 10. As far as I know, the numbers within this system for any one model are sequential, so the original 102 presumably started at 102000001, though 4744 is the lowest I have seen. The highest number on my list is 102023??? (last 3 digits missing, can't remember why.)

The lowest I have for 102A (with No 6 brake) is 102041955. But the No 6 brake was made available as a conversion kit for the original model, so there may be some apparent 102a's around with lower numbers than would be expected.

No records survive of these numbers, so it is merely a matter of recording examples seen. The serial numbers from 1936 are on record, and there is no logical sequence; random blocks of numbers were allocated to various EMI models in advance, so the numbers are of no use for estimating date. They can be found by reference to the original list, though this is unnecessary because those coded dates referred to by Ian Calderbank give the the date. (The 'B', by the way, is the code for Acoustic Gramophone.)

Just to mention, there was a lower number than 4744 mentioned on the following link (No. 2879) for you to see - also mentioned earlier in this thread:

http://forum.talkingmachine.info/viewtopic.php?f=14&t=36580