After giving it some thought. I decided to not restore my original seat frames with the rare option of factory installed head restraints for 1968 firebirds. I will keep them for the next guy or sell them.
I am looking at the Procar rally xl bucket seats or their pro-90 series for my 1968 firebird.
Does anyone have any experience with either of these bucket seats or have suggestions for a good bucket seat that fits the era but with good lumbar support and decent bolsters.
I go on long cruises so although not a fan of the modern look, my lumbar says otherwise.

Food for thought 1968Blackbird. Since you want lumbar support, have you looked at 3rd and 4th gen Trans Am and IROC Camaro seats?

Herb Adams used Recaro seats in his quasi-race car Fire Ams.

Recaro seats were installed in high end Trans Ams in the mid-80s, as well as some Fox body Mustangs. My ‘86 Trans Am is 1 of 2000 Recaro TAs for ‘86.

Lear Seigler made multi-adjustable lumbar seats for 3rd and 4th gen cars.

Procar makes a great seat to be sure. However there is a lot of choices from past GM cars or other OEMs that you might be able to find in wrecking yards or online too. You can adapt them to your first gen. Lots of folks have taken 2004-2006 GTO seats and put them in older Pontiac A-body cars. You can do the same with 3rd and 4th gen seats.