During a garage clear out I have rediscovered a Lucas King of the Road h/lamp from a 1930 Model 2 together with fork brackets. Did all Sunbeams of that era use the same fork fittings?
I am not sure this directly answers your question. However if you can identify the part number then it is possible to search on the part number to see what other models used the same part. This is the link to Sean Kelly's excelent parts list https://www.sunbeamland.com/partslist/ (https://www.sunbeamland.com/partslist/)
Sometimes Sunbeam used the same part on multiple models but just changed the first digit in the part number, so its worth searching for the last n digits.
Graham
Unfortunately, the parts lists don't include the headlamp brackets until the 1936 issues! Best bet might be to look at the catalogues, but I'm not sure if even those show headlamps.
P.
Many thanks to Graham and Paul for their advice which is much appreciated.
Jim