A small progress report. Yesterday a fiberboard piece was cut to raise the piece in the mold (to make the cutout rectangle sit higher). This was attached to the piece using double sided adhesive and then a mold box was made using common cereal cardboard (coated side facing inward). The piece was attached to the bottom of that box to keep it stable. Then the 2 part silicone was mixed (it took 100 ml), poured into the mold box and tape was put across the sides to keep them from falling outward. Then the silicone was poured in and this was left for apx 18 hours. Removed from the box this morning and all looks okay...a couple of spots I didn't exactly like but I believe it will be okay. The slight defects look to be "innies" which will leave "outies" on the finished piece which can be sanded off after the fiberglass cures. After the mold sits for a while I'll see how it does with fiberglass cloth and resin.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end