Short answer...no shops in Knoxville I have ever used. TPI 4x4 is down the road about 2.5hrs so maybe an option if parts are needed.
Long answer, i can check my spare 40 3rd member, if its complete and will get you home its an option (think i even have two decent shape gaskets). Yes, not same ratio and would introduce rework but if in a bind i would consider as axle splines, etc... are all the same. Only other difference may be bolt pattern on pinion flange. Don't remember if 3rd i have is from a 3spd or 4spd 40.
Undesirable option but i have had to drive on a front end before when i destroyed a rear end several years ago (broke pinion gear in half). Guess depends how far into Virginia you are headed.
Send me a PM if interested in taking a look.
Nik