While sorting through my stash of old custom wheels, I set this pair aside as Keystone Klassics, but later inspection introduced some doubt about that identification. I set them beside a set of 14" Keystone Klassics and immediately noted a difference in construction. The spokes of the Klassics were joined by an outer ring which was then welded to the rim, but these wheels' spokes, which appear to be alloy or matte-finish metal, are welded directly to the steel rim. Scrutiny with a tape measure expanded the mystery. Although these are 15" wheels, they are very narrow, at 5 1/2", and have only 2" backspace. The bolt pattern is conventional GM car, 5 on 4 3/4". Does the style/construction combo bring to mind a specific manufacturer and/or model name?
We have them here in OZ,commonly known as Rockets,a small block of steel is cast into the ally centre so they can be welded to the rim.
Here is one on Ebay but it doesn't have that smooth rim that your's do. 130891577053 Here is one with a rim like yours. 130891578738 Different year or different width? Keystones had a reputation for breaking around this area in the early 60's although I never saw a broken one to back that up.
I'm now pretty satisfied they are early Keystones. Every picture I found of a Rocket wheel showed flat spokes with a single rib in the middle. The construction and backside casting pattern of these wheels is identical to the '60s Keystone on eBay. I will say mine probably are the first Keystones I've ever seen whose spokes were in natural alloy finish with no chrome at all.
Those are Keystone Kustomags! I have a whole matching set. Klassics have the webbing between the spokes and are kinda ugly in my opinion, these early ones are way cooler.
After googling images for Keystonse Klassics and Keystone Kustomags, I believe you have the definitive answer...Keystone Kustomags (and I'm old enough that I should have remembered the difference!).
Cool wheels, and much more rare than Klassics. Here's an ad from '66 and one from '67, just to further verify what you now know...
Man, $46.95 each! Of course, in 1967, I was drinking ten-cent cokes, eating 25-cent burgers, and pumping 28-cent gasoline. I bet the wheels have retained every cent of their original value.