Give them a few whacks and sort them out!
Well... carefully placed whacks with a hammer and dolly and get yourself a stud welder gun. Then you can use a slide hammer to coax the dents out.
Those floors look really good for a UK car, as has been noted. There's a real contrast between their cleanness and the state of the dogleg/sill return next door!
Replacing the underfloor supports is an option if you want to get the rust out the seams, but FYI, the ones like those from Andy Plant/woody are lower profile than the factory ones, which means the triangular gusset piece under the frame rail behind the tension/compression rod brackets at the front will need some modifications to create a smooth transition. My next Dixie update will show what I mean on this, as I had to add a new gusset to the new right frame rail, which I ended up making from scratch versus using the APS one (which was completely wrong; I think Andy may have altered the design subsequently). On the left, where the original chassis rail and gusset are present, I've got to replace part of the underside of the gusset to make it shallower to connect to the APS floor support.
