Front frame rail/a arm advice needed.

When I first got my 68 the upper a arm mounts were rusted off. I picked up a section of rail from a yard much the same as what you have and took it to a local shop that built rods. He sectioned in the piece of rail about 3" on each side of the a arm mounts. I had the car on the road for several years and never had an issue getting it aligned. The last time around when I stripped down the car for a rebuild I replaced both frame rails as both sides had started rusting out at the mounts again. This time i did it myself with guidance from my brother the body guy. The front section I picked up for replacement metal did not have the complete rails as someone else had taken to floors/rockers from the car already. This time I used 1/4 steel plated plug welded inside the existing rails and again to the new rails. It turned out very nicely and is now almost invisible. Here is a shot not long after it was done and before I had smoothed out all the plug welds. You can see three of them close to the fire wall. Somewhere I have pics in process but heck if I know where they are now.