Once aftermarket control arms came around with the Guldstrand mod built in, that modification faded away quickly. I'm surprised you came up with the Pozzi article, I haven't seen that come up in a search in many years, nice digging...
Just do the tubulars, much easier than cutting and welding on the sub frame. With the rear already heavily modified, matching that on the front will be expected. My resto-mod has turned more that way too, as time passes, but hey, you'll have a better car as a result.
If you're set on cutting, consider getting a different frame. Yours is a very early one and would bring a nice income from a 100% original restorer looking for it, just don't tell Kelly about the swap...
