well its time consuming due to the process build mold let dry glass let dry glass parts together let dry lots of drying
but id mock the parts up on the truck and make a wooden mold to locate the parts and fill the gap for the new part
then glass in the area for the new part get it perfectly smooth in there now if you want you can make a foam piece that will be the positive for the mold fit it to the truck then take it off and mold it
but heres another option make it 3 or 5 piece if you ever bust a part you will have the molds for the custom pieces if you bust a runningboard its a factory easily found part etc. but one thing i would do is a gap between the cab and bed itll look professional and itll cause less stress on the whole setup
but id mock the parts up on the truck and make a wooden mold to locate the parts and fill the gap for the new part
then glass in the area for the new part get it perfectly smooth in there now if you want you can make a foam piece that will be the positive for the mold fit it to the truck then take it off and mold it
but heres another option make it 3 or 5 piece if you ever bust a part you will have the molds for the custom pieces if you bust a runningboard its a factory easily found part etc. but one thing i would do is a gap between the cab and bed itll look professional and itll cause less stress on the whole setup