Could not wait to try my idea of welding the planet gears to the carrier. It was tough to draw that first arc, as I knew it was a one way street. The gears are quite hard, the carrier is soft steel. I used a stainless steel rod and my Tig to weld it, with the sun gear engaged to keep the helical planets in their proper relationships.
I found a nasty defect in the tranny. One of the bolts that holds the two halfs together was gone, and the casting was broken. May as well fix it right, hope the heat does not warp it.