Without sounding harsh, I would ONLY take him on if you could afford the worst scenario costs.
A few people on here have got buns from freeads, thinking they are doing the right thing, and doing their own private rescue as such, only to find the rabbits has extensive problems.
If this happens, is it really fair to get a rescue to bail you out of a responsibility you have taken on?
Rescues, especially at this time of year, have huge waiting lists. When we were taking buns in, we would always have a waiting list of between 20-40 buns at any one time. So why should a rabbit taking on by a fellow forum member automatically jump the waiting list for a place and take up funds needed by many other bunnies?
If you can afford any potential dental and other problems, then the decision is down to you