Heed the advise of the extremely qualified posters, above.
One thing that could be leading you astray are the moulded mounting tabs, pins, etc. in the kit fuse halves. While these are often very good, there are times when they are only aproximate. (Older, and short-run, kits will have this is spades.)
Having as many refernce photos as you can get can be very vital. This because you can sometimes find the "right" fit just in dry-fitting the parts together. However, that might not be the correct location for the various parts. References will help establish that.