I'm sure I read somewhere the suggestion that good science always gives rise to new questions and I think this is also true of detailed historical reserch. The more that we know, the greater our ability to ask yet further questions.
My impression is that aspects such as lighting equipment were not a great concern to motorcycle manufacturers. From the point of view of marketing, it was useful to have the 'latest' design from a reputable supplier, especially one with a substantial advertising budget such as Lucas as it would reassure customers.
I'd be very surprised if small updates such as an extra rivet or a small material change whether with revised part number or not (and Lucas tended not to if parts were 100% interchangeable) would have been restricted to model years. Certainly with Nortons which I know best, there are frequent suggestions that improvements were included on the last of the previous model year machines as well as next years.
I've checked the military VAOS lists for lighting fitments that I have for Norton WD contracts dated between 1937 and 1940 and they all specify the MT110 with part number 526118 or 526118 SG (this latter simply referred to 'Service Green' which was the current WD vehicle colour.
I have no idea if the difference between 526082 and 526118 was simply the colour. 526118 clearly changed from Bronze Green to Khaki Green with no change of part number during the period that it was specified.
We may just be able to ascertain a little more if the civilian list that you have also includes component part numbers as well as complete assemblies. I'd certainly be interested to see a copy of that document.
If you give me your email address I will send you a scan of it for your use only. It takes a bit to understand it but when you do it is pretty comprehensive, however it does include an error or two or even three, (it is from Lucas after all!), but these are mainly to do with the writers comprehension of models from firms that he can't have been familiar with. I would think that accuracy of the Lucas part numbers would be virtually impeccable.
I saw it recently saying that it was I THINK 1925. But, there are quite a few variations to it going from;
All brass body construction, to a
Steel body with a lens with flats like on a diamond, to a
Steel body with a lens having a rounded shape.
There were different versions of it too with I believe (but aren't certain) glass or plastic lenses.
If you find out which one was in use for both the 1930 and 1937 seasons can you let me know please. For BSA the seasons ran from August 1929 until July 1930 and August 1936 till July 1937.
Hello Brian
I have seen a 1926 Lucas booklet showing the Mt110 and SS47 headlamp MD magdyno.
My 1930 booklet shows a Mt110 and H52 MBD magdyno.
My 1931 Bsa parts catalogue lists either a H52 or MC140 headlamp presuming you bought the optional instrument panel. M40 headlamp was offered for models with Maglita.
MS1 magdyno was offered on all models, but so was KM1 and KSA1 magnetos.
It also lists horn and saddle types.
I am informed that carbide lighting was offered until 37.
My 1951 Lucas booklet has a wiring diagram for Triumph that was issued September 1951, so does the Lucas season start in September? The MT110 is still drawn in this booklet as well as the 480.
Not a 'spert on this subject, but why would Lucas have "seasons"? They made stuff and the manufacturers used is - or in some cases manufacturers requested specific parts to be made to spec so I understand.
But the motorcycle manufacturers ran to seasons, not Lucas, AMAL, Dunlop etc......
