I build mine in very similar fashion, though I also TIG them and file them so as not so show the joint line. I've attached a "before and after" photo below. My raw castings show the discussed projection. The above photo shows perhaps the most obvious example I've seen of it. In most of the Fraser magazine rifles I've personally handled the joint wasn't quite so apparent, but there none-the-less.

This too is the first Fraser I've seen using a 98. However, that is as Caprivi states...."with Daniel at the bench". You run across later model "Fraser's" on 98s, after they were acquired by Dickson and MacNaughton.