I just did all that on my '64 this spring, so a lot of it is still fresh in my old mind, lol. I'm gonna say that your setup is very similar.
Mine had a pedal there.... but after I removed it, and the carpeting, to por-15 the frt floorboard, I discovered the OP had simply left the broken stub of the original one mounted in the floor -and had redrilled 2 new holes to mount a new pedal over the carpeting a little north of the old one, -yep I had a good chuckle outa that.
So, after you familiarize yourself with the gas pedal's "spoon" setup already mentioned, and if the 2 sheet metal screws are totally rusted up and/or seized, try going from underneath with vise grips (the screws will protrude quite a ways). While down there you may notice that you have a little floor mounted u-shaped clamp there retaining the speedo cable. The gas pedal screws do double duty. If your floors are pretty decent like mine are then it might still be there. Otherwise, you might have heard this barely audible sound of something metallic hitting the floor after removing the screws, and wondered "now what was that??!". lol
If replacing carpeting, sound deadener, jute, etc ..... make sure the new pedal sits ALL the way down where it should, otherwise the pedal will bind on the 'spoon' up/down, and right/left. I had to wind up mounting my new pedal to bare metal, and made a nice little "window" for it thru the carpeting. I also corrected the "throw" on mine, always wondered from day one why the car didn't seem to accelerate as it should. So, check your throttle operation by using a buddy or your spouse (as I did), before you call it "done".
See photo I have attached -I have tons of additional photos, notes and experience doing mine, so holler if you need further 'splainin' as the project unfolds.
Norm
