Spicer and I had talked about using a 1/2 or 3/4" plate between the rim halves, with the bolts that hold the rims together holding the insert in, then have that plate water-jetted with the rockwell 6 lug pattern and the outer "beadlock pattern", a little clearance radius of the 10 bolt pattern ( duece pattern just barely intrudes into 5 ton pattern, say like 1/2" or so) on both halves is needed to clear the lug nuts, We had talked about indexing the pattern between the 10 lug so you could still use the rims on a 5 ton later if needed, other wise you could lathe the 5 ton mounting surface off the outer half. The original 5 ton mounting surface could now be a "rockring" for the duece lug nuts, but when I had the rims Spicer's got, it was going to be like $200 a rim to water-jet out the pattern then have them blanchard ground, then you just have to figure out the sealing, either RTV or cut an o-ring groove in both sides of the adapter center to match the 5 ton rims, then bolt them together and bolt them on the truck, this was using the "better' 5 ton rims that have twice the number of bolts(20), there are some that look like they are missing every other bolt...those aren't the "preferred" rims to start with, or at least that's what I was told but the guy I got my rockwells and 5 ton combat rims from...
so you would end up with stock 20 x 10 combat rims that were 1/2 or 3/4" wider and backspaced roughly 2 " less than they were stock, moving the tires out a little...
let me find the pics...