Don't know about a fix, but...
The early VII I have in SH3 (with GWX) has the rails in the 'correct' position. i.e. it has curved rails around the gun located on the foredeck which terminate near the front of the conning tower and continue back (with cables) until the cables meet stanchions approximately in line with the rear of the conning tower, the steel rails then continue again, extending a little way back onto the rear deck, although certainly not as far as the rails extend at the front. However, it's possible to find pictures of type sevens with very different rails - even for boats built in the same month - largely because of the different yards which built them. I've seen some pictures of earlier type sevens with (cable) rails running almost the full length of the rear deck, although, judging from photographic evidence, it appears these were deleted fairly quickly.
Chock