I'm impressed with your work mate, I'm doing a similar job. I have a '40 model which was restored in '83. and fitted with a tray (flat top). I always wanted a pickup, so 18 months ago, I bought a repro bed from the US and have been working on it part time since.
I have it painted & sitting on the chassis now, ready to line up & drill the holes for the mounting bolts. I also then have to make running board extensions, but am looking at getting a pair off another truck, then cutting & shutting them. I'll be interested in how yours finish up.
One problem I encountered was, as my truck has an Australian built cab, when the bed was sat on the chassis, there was a large gap between the front panel & the rear of the cab. I had to drill new holes in the rails, 60mm further forward. I assume that the Aussie Holden built cab is not as deep as the US Fisher one.
I'll keep on checking your progress, and will get a picture of mine up in due course.