I started the S-IVB portion of the build by adding the PE personnel access door to the interstage. The ullage motors had already been sanded to the shape desired.
Moving on to the S-IVB stage itself, I removed all the required molded in details. This consisted of the APS units and a small area next to the POS I APS. That was to be used for a piping cover that came in the kit. The kit part is too long and too small. It will be replaced by a resin part that is the proper size. The kit was made with four molded in antennas in the upper skirt section. Two of them had to be removed since they were not used for the manned flights.
I test fitted the RealSpace SLA/CSM resin part to the Mongram S-IVB. I immediately noticed that there was a fit mismatch. The SLA was too small compared to the Instrument Unit on the S-IVB. I masked off the molded in stringers of the forward skirt and then used a sanding stick to sand the IU down to a smaller diameter that would match the SLA.
I’ve now got all the PE details attached and most of the resin bits. The APS units are not attached yet since I’m not sure if I’m going to attach them now or wait until it is painted. All the kit parts that I’m going to use have also been added.
It’s almost time to move on to the RealSpace SLA/CSM replacement parts.