WOW, a new light unit for a 68 year old car.... now that's a big ask!
To help you find one there is a list of alternative part numbers on page 31 -
https://www.mg-cars....df/altparts.pdf
Have you checked out the MG Y Type Register yet? -
https://www.mg-cars....contactus.shtml
5 hours of searching & all I can find is a complete Fog Lamp assembly-
http://www.ntgservic...nal-SFT575.html
Expensive! but you could sell your existing light to offset some of the cost.
Other alternative are....
Get your reflector re-coated - not going to be cheap as it requires a specialist to do the job.
or IF the lens & reflector are held together with an adhesive sealant then find/buy a unit where the reflector is the same diameter & profile, use the new reflector & use your original glass lens to keep it looking authentic.
I've used this method on (more modern) lights when i couldn't find 'New Old Stock' replacements.
Edited by Itsaminithing, 29 August 2021 - 05:14 PM.