Dan,
My advice is dive in.

If you are in the industry it's just more metalwork.  Keep your fits close, study the function don't overlook the obvious.  The ODG's (old dead guys) knew a lot, learned a lot, the hard way.  Don't go into this thinking you won't have any scrap, you will.  As a hobby, nothing for hire, nothing for sale, I build a lot of single shots in a year.  I shoot quite a bit with them and prefer to complete with only the ones I build.  Put your ME experience to work and you'll find it's a fantastic release from the day to day grind. 
My 2¢ 
Greg

LRF, Thank you for the prints. I received them today. 

Thank you to Bobw for that thread. That is very useful.

GT, thank you for the encouragement, Looking at the prints there are definitely a couple items that confuse me as well as a couple of features that will take some head scratching to figure out. 

My first question is, is the breach block tapered from top to bottom? The print makes it look like it is, but the top has no measurement and the receiver does not appear to show a taper. I would think that would add a significant challenge to cutting an accurate square hole if it was also tapered. 

I do plan on making a solidworks 3d model so I should be able to check most things before they get made but I know I'll still miss stuff.