Commando rear indicator mount bracket

Does anyone else have rear indicator mounting brackets that are threaded so that the indicator stalks screw into them? The fractured one I've just taken off my '72 Combat does have threaded holes in the brackets and yet the remanufactured replacement part from Andover Norton has just oversize plain holes and requires spring washers to provide locking.
I have it in my mind that both the Combats I owned in the late '70s and early '80s both had these threaded brackets, yet AN says their official part diagrams show simple untapped holes. It strikes me the threaded brackets were a superior design because the nuts both sides of the bracket were ony there to lock and prevent the indicator stem from rotating.

My 1972 (engine no. 200***) just has plain holes. I use strong spring washers to help stop them rotating or vibrating loose.

Just dug mine out of the junk (I mean sacred original parts) box.... no threaded holes. Jan 72 202xxx. Also the rear turnsignal stalks each have 2 nuts on the mounting end of the shaft