Jeff,
A little history lesson may be in order I heard this from Harvey Weidman who is along with his brother Al, probably the world's leading expert on Porsche wheels. Back in the '70's the dealerships did not have a great "margin" which means the amount that they made on each car sold. For that reason, they would do things to pump that margin. Rust proofing (that worked well
), mud flaps, alloy wheels, window tinting, aftermarket radios, etc were all methods that they used to pump their margin. Harvey tells me that the 914's would come in with factory 2 liter Fuchs wheels and they would take them off, put on Western Wheels and upcharge the customer for "alloy wheels". If your car is an appearance group car, you can almost be sure that was the case with yours.
By the way, I love that color and your 914 is in great shape. Cute kids too!