Need Confirmation
 

Federation rules: R2 on 2nd, R1 on 1st. B5 gets a hit. R2 rounds 3rd and gets in a rundown between 3rd and home. During the rundown, R1 safely makes it to 3rd while B5 goes to 2nd. R2 gets obstructed heading back into 3rd and is tagged out.
Please confirm this ruling: Umpire declares Dead Ball and awards R2 3rd base. R1 is sent back to 2nd and B5 back to 1st.

Yep. R1 owns 3b until being retired or reaching home

And presumably was judged as would have reached 3rd if not OBS.

But even if judged to not make it back to 3rd without the OBS, we still need to award her that base since she can't be called out between the two bases where the OBS occurred. Right?

R1 judged to have reached 3rd without putout if no OBS and judged not to reach home.

Correct about protected from out, given no exceptions.

The runner cannot be called out between the two bases where obstructed. The runner obviously wasn't going to reach home safely, so you have to place the runner somewhere and it cannot be home. I believe there is no doubt that is 3rd. And if there are other runners, they also need to be placed.