I think I would be more surprised if it "couldn't" be done. I mean, if you have the tools and wherewithal most anything can be accomplished. I recommend you go for it, take lots of pics and share the build and results. I am sure the ILF crowd would love to see it as well as the Bear crowd. Beyond that, there are a lot of decommissioned Bear bows out there. I am guessing if someone created a frankenbear it would start a whole new trend and possibly a new thread category here.
If it were me, I would certainly start with consistent and easily obtainable limbs. Probably an ILF set up would be best but at the very least some from a bowyer that is using CNC machines and is currently in production with a lot of limbs already out in the market.
I say this for two reasons: 1. the first swing of the bat may find the bow too heavy or light due to riser to limb configuration so having access to bolt on a different set(length, weight, etc..)would be priceless 2. the process would/could be repeatable for others and/or yourself if it turns out to be awesome!!