I had the same question on FB recently, this a very rare in-between model, with a plexiglass glass.

It's 1941ish, not much info about them at all. I have one myself.

Cheers,

Lex

email (option): welbike@welbi**.net

Hi Lex, that’s right it does have plexi-glass. I thought someone fitted this as aftermarket.

Regards
Brandon

It's a rare clock. Worth putting on the shelf and admiring. It would be a shame to do a service-exchange with it.