Those wheels are aftermarket and were never offered by Volvo, as for Sweden. I do not know about the rest of the world if the dealers kept themselves to Volvo's policy and not sell them. As mentioned for 123 GT, they had the same wheels as 220, 4 1/2". If I do not remember wrong, Lemmerz should have a smoth inside of the rim, and the Kronprinz should have a grove (supposed to be a safety thing so the tire would not come of). Personally I like the design of Lemmerz better.

In the late 60's and early 70's, Volvo did indeed offer 3 different 5.5J x 15 steel wheels for 544's , 122's and P1800's in Germany. They were as follows.
1. Kronprinz #6136 B with a 20mm offset.
2. Kronprinz #6134 B with a 30mm offset.
3. Lemmerz #1538 with a 30mm offset
Wheels from the same manufacturer were also offered for the 140 Series of cars in the late 60's early 70's. (With the correct bolt circle)

IPD also offered one of these wheels in the early 70's in their catalog. They were on a P1800 F Production race car I purchased in 1971.

I believe that both companies were/are OEM suppliers for most european car manufactures.

I think you might find these are Lemmerz and are the "rare" "Kron-Prins" wide wheels that were available for the 123GT from Volvo. This would tie in with the age of your car so they might even have been fitted from new. I have a rather rusty set of these for my Amazon. They may be beyond help and are stored away. If I can get at them in the near future I'll see if I can confirm the number.