With the help of friend, we did not do a frame off resto, but I know I R&R'ed every part at least once on my Vette, and some stuff 2-3 times. I did the exact same thing with a Sunbeam Tiger.
Cloning an 1967 L88 sounds great on paper, but I get the chills just thinking about how expensive it would be to buy
just the special air cleaner setup for the L88 hood.
Just a guess, but I bet a quality repro of the L88 hood is probably a couple grand.
And if you don't have the soft top frame...look out.
I love mid-year Vettes, but I don't even want to look at buying another one in this lifetime. I applaud SPF for bringing the 289 and the GS to market in this or any economy. I hope they continue R&D on new products for the future.