So here's what I ended up doing....First I found the Hurst stick layout charts on their website and found a replacement stick (No. 6836) that in part had the same geometry as the Mustang shifter (approx. height and reach).
Then I cut off the portion that bolted to a stock Hurst shifter and welded it to a CNC machined part that replicated the Mustang base I had made by a local machine shop in approx. the same alignment as the reversed Mustang shifter ( I let it sit a little more vertical than the reverse Mustang so it would clear my knee a little better)
I found that the stock rubber dust boot hindered the shifter somewhat, so I went with a leather boot to complete the look. And it shifts a little smoother and in a more natural line than the Mustang stick. It's what I had back in the 60's and I love the look.
I kept the Mustang stick intact so I can simply bolt it on in the future if I want a change of pace....