Permanent cowl cleanouts?

With the '65 Formula S now in the shop, l asked my bodyman/painters to cut some access holes in the lower front corners of the front cowl area so they clesn up inside there (rust treatment, prime, paint). I was thinking when they finished, the access holes would be closed up again (welding the cutout pieces back on and hiding the "scars" with body filler and fresh paint.

However, they have the idea to find some oval shaped body plugs, cutting the openings to size, completing their repairs/refinishing inside the cowl area, and finally simply plugging the holes using the oval body plugs they found. That would provide easy cleanout access in the future. I thought that was a good idea.