Don't tell me, let me guess--you are planning on developing a wheel knock-off tool that won't infringe on the Oldtimer design, yet can be had for 25% of the cost of that tool, right?
(I just happened to stumble across your post on the Club Cobra forum...)
Years ago I had a plan to modify an existing inertial knockoff tool sold inexpensively by Speedway Motors:
Speedway Nut Smacker Knock-Off Tool - Speedway Motors, America's Oldest Speed Shop
The program completely stalled out due to Life Problems interfering with the machinist/engineer who was going to implement my idea. However, he just emerged a few days ago and is back in the saddle. I just removed a spinner from my Cobra (spun a bearing back in November, so the car isn't going anywhere anyway!) and will be bringing it to him next week.
The basic idea is to weld three arms splayed 120 degrees apart, to the existing hub of the tool; a heavy-duty delrin piece with three slots for the spinner ears will then be bolted to the three arms.
I hope to have a working prototype in a few weeks. Assuming it works as intended, he might then be convinced to put them into production for mass consumption. We'll see...
And in the meantime, there is an existing solution that merits consideration:
http://knockoffspinnertool.com/cobra...brand_spinners