The Stovebolt Site Forums The Shop Area Paint and Body Shop Exterior mirror locations?

A previous owner changed the mirror set up on my 53 P.U. I have ordered original style replacements but am unsure how to relocate the original holes. Are there steel backing plates with bolt holes behind the sheet metal to attach the mirrors? I would prefer not to have to hunt around from the outside with a grinder. Looks like I will have to completely pull the heater for access on the passenger side.
Also would appreciate any tips on filling the holes that will be left on my doors.

Yes there are holes in the metal supports under the cowl on both passenger and driver's side. You should be able to locate the holes by using a punch from inside thru the holes in the supports, then drill from the outside.
As far as filling holes on the doors, just weld them shut and grind smooth. You may want to put a copper backer inside the door before welding to help prevent burning thru with your welder. Holes less than 1/4" can usually just be welded shut, but for larger holes, a piece of sheet metal cut to fit helps reduce the amount of heat and shrinkage.
Here's a before and after of a 3/8" hole on the roof of my truck that had signal lights installed.

You wont have to pull the heater on the passenger side, just the glove box
Yes, there are backing plates behind the sheet metal.

I used a spring loaded center punch from the inside, then just drilled through the dimple from the outside.
There are 4 holes in the support bracket on the inside. Make sure you use the correct ones.

Ive attached pictures from Denny Graham's web site to show passenger side.

Drivers side similar

Not sure on the level of restoration your accomplishing, my 50 has a fiberglass/body filler repair on west coast mirror holes in the door. Its held up for 39years.
Weld repair would be better.

As often said/posted, Thanks Denny
and, Thanks DADS50

Another view originally from LonnieC.

Thanks all ! The expertise and experience found here sure help a struggling amateur ...