A note on Serial Numbers
Many examples, produced before 1912, lack any form of numbering - even assembly stampings are absent (those numbers and letters used to identify components as belonging to a particular machine as a batch was built up). In addition, various prefix and suffix letters have also been found - yet not recorded in the factory archives. The possibility is that these marks were applied to a batch as intended for a particular dealer - or an end customer who ordered more than one example. For some unexplained reason early B-Type lathe individual serial numbers were allocated to two machines - and there is always the possibility that this practice occurred at other times, but was not recorded. Also lost in the mists of time is when the digits were stamped: this could have been upon completion of a build, or immediately before dispatch - in which case unsold, obsolete models might have carried numbers from a sequence being applied to newer version. Many examples discovered in recent years shows exceptions to the listings below and so, much as we would wish it, nothing is certain.

3.5-inch Flat Bed Serial Numbers
Yearly figures from introduction in 1902 until the heavily revised B-Type of 1912 are not known. However, records have been found of obsolete models dispatched during 1914 - presumably from stock not sent out to dealers. These were:
Serial numbers: 593, 609, 614, 615, 629, 633, 643, 644, 648, 651, 662, 664, 668, 669, 671, 675, 681, 682, 684 and, in 1915, Serial 501.
As B-Type Serials started with 700, it might be deduced that only around 600 of the first model were produced  during the first ten years. At an average of just over one per week, that does seem a very low figure.
Although the B Type was replaced in 1921 by the new M-Type it is believed that production had stopped in 1919 with large stocks unsold. Most were gone by the end of 1920, though a few lingered on until 1926 - the last of the batch being Serial 4226.

B-Type Serial numbers:
1912 - ( ? )
1913 - 1914 Serials 700 to 1516
1914 - 1916 Serials 1517 to 1731
1916 - 1918 Serials 1732 to 2003
1917 - 1918 Serials 2003 to 2173 (separate pages in ledger)
1918 - 1920 Serials 2173 to 2338
1919            Serials 2339** to 3002 (separate pages in ledger)
1919 - 1920 Serials 3003 to 3464
Serials 3465 to 4058 (separate pages in ledger)
1920            Serials 4059 to 4190 (separate pages in ledger)
Serials 4191 to 4224 (separate pages in ledger)
**Lathes up to No. 2339 had two machines against each Serial Number i.e. two different customers, dates and production ticket numbers for each Allowing for numbers duplicated, total production of the B-Type would have been around 4000 units.

Power Feed BS Type
The makers did not distinguish between these (power cross feed) and ordinary models in their record keeping

M-Type Serial Numbers
Introduced in 1921 and further developed in late 1924, the M-Type continued little changed until production was taken up by Myford in 1943. Some pre-production examples were manufactured during 1919/1920.
1919 - 1920 Serials 1 to 66
1920 -          Serials 67 to 131
1920 - 1922 Serials 132 to 1121
1922 - 1923 Serials 1122 to 1319
1923 - 1925 Serials 1320 to 1649 "A" suffix applied from No. 1405A--but at random
1925 - 1926 Serials 1450 to 1887
1926 - 1927 Serials 1897A to 2226A
1927 - 1929 Serials 2227A to 2685A
1929 - 1931 Serials  2686A to 2949A
1931 - 1933 Serials 2950A to 3345A
1933 - 1935 Serials 3346A to 3675A
1935 - 1937 Serials 3676A to 4071A
1937 - 1939 Serials 4072A to 4203A
1939 - 1941 Serials 4204A to 4401A
1941 - 1942 Serials 4402A to 4467A
1941 - 1942 Serials 4468A to 4592A (Separate page in ledger)
1943 -          Serials 4534A to 4592A
A pattern machine (presumably a sample) was dispatched to Myford on March 25th, 1943 and the final M-type from the Drummond production line was sent to the Admiralty on the June 30th of the same year.

Round Bed Serial Numbers
Machines with an "A" prefix are pre 1920 - afterwards "0" was used. However, on some machines this is missing - while others have no Serial number.
Yearly figures from the introduction in 1908 to 1912 are not known - but thereafter factory records show that:
From 05/07/13 to the end of 1914 Serials 5300 to 6175
1914 to 1915 Serials 6176 to 6379
1915 to 1917 Serials 6380 to 6515
1917 to 1919 Serials 6516 to 6719
The above figures show that just 543 examples of the Round Bed were made during WW1.
The next set of records started with a new numbering system - a prefix "0" being used. However, although Company ledgers record the "0", research shows that it was not physically stamped on every machine.
1919 Serial numbers to 0680 (the start number is not known, but might have been 0101)
1920 to 1923 Serials 0681 to 02144
1923 to 1924 Serials 03398 to 03991
1924 to 1926 Serials 03992 to 04585
1926 to 1928 Serials 04586 to 04981
1928 to 1930 Serials 04982 to 05377
1930 to 1932 Serials 05378 to 05641
1932 to 1935 Serials 05642 to 05905
1935 to 1938 Serials 05906 to 06103
1938 to 1943 Serials 06104 to 06193
The very last Round Bed was sent to Myford on May 18th, 1943.
Total production from 1908 to 1913 around 1500 - and the grand total 9253