Need some advice

Hi all I have a discovery 1 this evening I removed tow bar with the help of an angle grinder as all the bolts were siezed solid I was hoping to fit the hang down recovery points at rear but the tow bar bolts are rusted into the chassis big time and refuse to budge even with a big adjustment stick I'm now thinking as I cannot mount them there making a plate the bolts through the back cross part of chassis where top tow bar bolts went that come out under rear bumper and having a central recovery point has anyone done this before or have any concerns that I may have overlooked
Thanks in advance