Can't help with the mount Don, but is the same friend you helped with the horn a few years ago (I think he was pushing everything else but the horn button)?? 
No, different guy Bob. That was Rob and he's not allowed to have tools close to anything with wheels including a lawn mower or a match box car. He doesn't even have a bike anymore.
Just came back from looking at this Road King. Got to say that it's got me stumped right now. I think the mount that came out was a Velva mount. 1/2" thick center aluminum plate. The stock mount has an 1/8" thick center steel plate.
The differences in the center plates aren't an absolute guide though. The center body of the mounts could be different too and the bad mount that came out was so torn up there's not much to compare against.
What I do know, however, is that if I bolt this new HD 16207-79D mount in the bike it pulls the engine down too far in front. Front piple isn't touching but gets too close to the right down tube and the oil filter does just contact the regulator. Zero clearance and a slight bit of pressure. Something there wouldn't survive in long term service.
There's not any kind of spacer between the frame and the mount on the old Rev A and B mounts. But I've never installed one of these Rev C or D style mounts before. So while I can assume ...
Wait a second. Dammit. Think I just thought of it. The stupid things you don't think of when you don't do this stuff everyday and not all the pieces are always familiar to you. Dammit.
When the thicker Velva mounts are installed the top mount plate moves up from below the front engine bosses to on top of them. With the thinner OE mount that plate would have to go back underneath. Those engine tabs are at least a 1/2" thick. That will raise the engine back up.
I was just putting it back together exactly like it came apart. I've got to move the top mount plate back down below the engine mounting tabs. Chit. I'm an idiot.
Thanks for the sounding board Bob. You got going in the right direction

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I know he's still up. Going to go finish that little bastard tonight.