I was gonna say someone already clipped the front suspension.

If you wanted a Mopar suspension clip under your Mopar 30 years ago, the Volare clip was THE way to go. Everything was mounted to the subframe, and the subframe was mounted to the original car with 4 bolts through bushings. Though not a perfect design, and it was a bit too wide (as were most clip options of the time), it was much easier then adding separate suspension pieces (crossmember, upper control arm mounting, and lower control arm mounting).

I ran a 35 Dodge with a Volare clip on it on the road for 7 years and 66,000 miles. The clip is wide for the 30s cars, I moved the front fenders out 2" per side for tire clearance, but adding 2" to each side of the grill shell, or the area between the grill and the fenders on a 39 is going to be a much bigger challenge then it was on the 35. These days, several modern factory steel (and mag) wheels are made that would move the wheel inside the fender, provided they clear the brake rotor and calipers. Early Dakota 5 bolt wheels (and others) will bolt onto the Volare rotors, but I don't know bout clearance issues.

The Volare clip on that 39 was not installed using the bolt on method, they cut the Volare subframe ans welded it to the frame rails. Many people did that with the Volare clip, because it had awkward bolt up locations. Welding it on eliminated several lbs of steel Mopar added to the subframe for the bolt on purpose. The biggest issue with welding it to the frame is there is no room for error. If the install was center correctly, all is good, unfortunately, there is probably no way of knowing until you drive it down the road. Measuring may help, but where would you measure from? Es specially since the rear suspension has been modified as well.

The yellow fender looks to have about the correct curves, but it looks a little short to me, 39 rear fenders are pretty long. Depending on what is cut on the current 39 fenders, it might be easier to repair them. The original wheel opening was pretty small, and the fenders are not very far away from the body, wide rear tires run very close to the fender lips. Cutting rear fenders for tire clearance was often done, back when the Volare clip was a popular clip.

Floor boards and trunk floors are pretty flat. If you posses the skills to build the rest of the car, the floors shouldn't be an issue. The floors in most old cars and trucks are toast (at least in my world). If you decide to use the Dakota frame, the Dakota floor pan will work in the front, and the Dakota box floor works well from the cab floor back, at least it seems to have worked out OK with my 48 Plymouth.

From what I see in the pictures, I would check to be sure the front clip and the rear clip are square and inline with each other. Given that being correct, I'd finish that guy's start, it looks like a good base to build from. You are still 1,000 productive work hours from being road worthy, and then several more hours from being a "show" car. If you start over, your 2,000 hours from being road worthy. Gene

Dave, sorry you had to pass on the humpbacks,
if I had any cash flow I sure would buy them...
but this coupe will be so cool too.
I had a volare frontend under my 36 humpback and it rode and drove great, I also used a "B" body 3 3/4 rear end in it
that is a good set up for your coupe if its in right.

like was said above they are wider than a mustang II so you cant lower the car as much as some might like.

I wanted to get my humpback really low but the tire rubbed the fender slightly on tight turns and I had to settle on where it ended up, it worked out great in the long run.

the fenders on the coupe look saveable to me, if you can find other ones great but yours look workable to me.

like Gene said the dakota is a little wide also and might work with the right offset wheel.

I would make it work even if I had to widen the fenders a little

I have a 40 Ply sedan delivery project that I think will get a dakota chassis, if not I really like the Mustang II style front ends with tube "A" arms and 11" rotors

just a few thought and you will need to deiced which way to go on the coupe, good luck with the project.