Removing the parts from the mold for the seaming operation is a no-no. The layup will wander & you wil very likely build in warps. Use the mold itself for alignment, you spent all that time to make a straight plug right? The pics of the jog seam sub-plate shows the proper way to do it, especially if you can't get tape in there. You can even vac bag the layup with this setup.

Another trick if you want to use tape or similar
- use 3M spray & dust a coat on the seaming tape
- apply the tape so that half of it is stuck to the trimmed layup, the other half is sticking up
- (ideally but not required) do the top on one mold half & the bottom on the other mold half
- now wet out the tape with epoxy, a bit on the mating surface & lay the molds together sp that one tape flaps inside the fuse, then the other
- usually you still have to give it a wipe with a brush on a stick, but at least this keeps the joint very straight & positioned.