Yesterday I re-attached the airlines to the main gear after trimming off the first 1/2 inch thereby making the connection to the air nipples with fresh line. I re-pressurized the system and the gear seemed to have a little more push when I held my hand against the retract motion in an attempt to duplicate resistance the airspeed might offer. It was slightly stronger which might lead me to believe the fresh connection did help.
I then re-connected the lines that normally go to the wing to each other as discussed earlier. With the retract valve in one position there was no air hissing but in the other position the hissing returned and was more pronounced. It was definitely coming from the central nipple that connects to the air tank. I believe the valve is the most likely culprit but the increased volume of the hissing also tells me the main gear connections were weak. When I get the new valve I will install it and repeat these steps. If no hissing, then I will test fly. Hopefully no more skidding in on the belly pan.
I'll post as soon as I get more results.