Hi.
Some companies - Fender, in particular - have a support section with body and wiring diagrams in PDF format. Those can be opened in Adobe Illustrator and scaled to actual size, easily enough (as long as you have a couple of "real life" dimensions to match/scale to).
I just visited BC Rich's site, looking for something similar, but there doesn't seem to be.
But I know I could draw the thing in Illustrator easily enough (are we just talking the body perimeter?), with some good, straight-on photo references or templates. And then if I had a couple of accurate references measurements (body at the widest point and/or overall length), I could scale it up to that, and you'd have your full-size scale plan, e-mailed to you as a PDF or whatever. Getting into the other stuff (pickup and bridge routing, controls, etc.) would require a bit more work and research (and lots of accurate info and measurements) you'd have to provide (I don't have any BC Rich guitars at my disposal), but I've done it before...I usually do my Tele and Dano mockups in line-art/outline style at full scale in Illustrator, then export - and shrink them down a skootch - for "dressing up" in Photoshop.
Otherwise, fire up Google and search around for Eagle plans...maybe something's out there?