Can be done, you chisel off the spot welded cap ring on blow rim steering wheel, then mount a stock 72-74 challenger/cuda horn assy by drilling and tapping for the 3 small machine thread screws, take the steel horn button plate out the plastic 72-74 horn cap, transfer it to rim blow cap, I've done it for 2 of my E bodies

The Cuda blow rim cap lends itself to this swap nicely, the Challenger cap required me to machine a new outer decorative horn cap ring out of aluminum to make up the space the cap was raised off the wheel, rather tedious, and you need a milling machine and lathe...

Member Brad70 had an alternate idea for his tuff wheel, which you could apply to your I assume 1970 Challenger...Brad also makes/sell a number of Mopar related items should you wish to pursue this endeavor?

Here's a link to his blow rim capped tuff wheel project...

https://forum.e-bodies.org/interior/6/tuff-wheel-with-rim-blow-dodge-cap/311/