The command Module id a Chris Trice Glass Fiber component (top of the line, the best you can get) and came to me partially assembled. The two halves were not very well joined (strength) but were well aligned. I did a quick re-fix and then used some epoxy and tape on the inside to make a strong fix.
A quick coat of primer after a soapy rub down to prepare the surface.
My Airfix models and Command Module are filled across the seams with Vallejo Plastic Putty. I will leave them for a day or two so that any shrinkage can occur before I rub them down.