Nice Wheel.
I worked for VW through the 70's and this type of wheel was often specified on the MK1 Scirocco models as an extra. We fitted some to Golfs and the occasional Passat. (the same was fitted to Audi 80s back then, which were effectively a Passat with different badges, trim and wheels)
I don't remember this having a VW Part Number and in those days we had an Accessory Folder (Ring Binder) to show Customers the small number of Accessories we had on offer back then.
Most Accessories had part number that began 111 999 and this covered everything from Wax Polish to Tow Bars!
I the case of this steering wheel I have a (vague) memory of it being made by VOTEX and know that it was available for fitting to many other makes Cars such as Opel at the time. My friend had an Kadett with this wheel fitted.
Very often our Accessories back then came with the original manufacturers packaging and we at VW simply added our part number sticker to make it our own.
The Badge on the middle was supplied to us in the box with the wheel and replaced the proprietary one that was fitted to the wheel. I can't remember if the button was a 'genuine' item or was what we called 'after fit'.
ps; By way of interest the replacement 'GT Beetle; Rear Engine Lid Badges were also listed in that Accessory Folder as a 111 999 Part Number. I bought all the remaining ones from VW UK stock in the late 70's.
The replacement badges were chromed plastic and pretty poor quality sadly.