Maybe I misrepresented myself on this, but this is the Bivins small Lancaster BP.
I started out by eliminating some of the curvature and then proceeded to make it up, after I was happy with the fit I drilled and countersunk the holes.
Scary Part...
I then took a 4" handheld grinder and started removing everything that didn't look like a slim BP, I then took a half round file and evened it up and finished with drawfiling to make it like I thought I seen in the books.
Thanks a bunch both of you for your input, and I feel you are correct Dave as most of the castings are to fat.