Hi Bill,
So the more I thought about it the more I disfavored breaking up my 1/2" npt tapered manifold to cannibalize the center section. Then I remembered I had a newer USD manifold on my beloved (but alas bad alloy cracked neck yellow twin 50's I bought new in the mid 70's). So I took that center section, replaced the black on/off knob with an old-style one, and viola, a new center section for my steel twin 45's ! Plus I get to keep using a piece of that old rig I had so many adventures with over the years. I have pleased the vintage overlords.