Help identifying custom 1911

Hi.  New here.  I just purchased a 45 wadcutter gun  It has the following.  A Bo-Mar rib with accuracy tuner, a Checkered front grip strap, the barrel is unmarked.  The frame is a 70 series frame (70GXXXXX serial number) and a pre-70 commercial slide.   The ONLY marks on the gun from the builder is "MBM" and a code number on the slide bottom (where the disconnector rides) and the same initials and code on the top of the frame in the area of the disconnector.  It looks just like any other "heavy slide" 45 of the era.  Would anybody know who might have built this gun?  I haven't shot it yet but it should be accurate. It doesn't look like it's been shot much. 

Thanks

W

Sounds like a nice one.  Can you share some pictures of it?