Opinions on Duster Front Clip/Frame R&R

This is a take off from my thread "Demon Clone Project". I'm placing it here because it's not part of the Demon build.

I have two '73 Dusters, a '74 Dart Sport and a complete '73 Duster front clip, with the frame cut just ahead of the firewall.

I've decided to make the Dart a Demon and have the front clip parts for that as well. Rather than trash the 73 that's an original 340 4 spd car for parts I plan to replace its front frame damage (both rails bent) with a front clip and frame rails and sell it as a roller to help fund the Demon.

Of course everything will be well documented. All critical welds will be done by a professional certified welder.

Here's the initial plan. Use the spare front clip with a frame splice just ahead of the firewall. I've researched unibody frame splicing and the method would be to make a U shaped sleeve to fit inside the frame about 12" long, make the cuts a 45, tig weld at the 45, and plug weld the sleeve, staying clear of the lower portion of the frame rail (high stress area). Fish plates on the outside would be an option. A jig attached to the frame rails rear of the firewall would line things up. Diagonal measurements as a backup. Front bumper support on clip and K member keep the clip square.

Here's the alternate plan. To avoid a frame splice in the high stress area ahead of the firewall I could use full length front frame members and front clip cut out of the other blue 73 /6. I'd need to make a longer jig attached to the rear and front transverse frame members. It would be a lot more work.

I feel the orignial plan would provide a solid result but... I think a buyer might be more secure about a full length frame member. Unless I get a lot of feedback otherwise that's the direction I'm headed.

Tell me what you think as a potential buyer.

Pics: brown 74 Dart
yellow 73 340 4 spd Duster (bent frame rails not shown)
blue 73 /6 (major side impact, good front end)
splice location for original plan (undercoat makes 45 there by chance)