You can use the old stripper hole left from the roll pin that held the stripper clip guide to hold the mount. Granted it would require the work of a good gunsmith to mount the scope rail and then drill the hole in the rail and then tap the receiver all while aligned but I think that would create a very secure rear mount bolt. Or you can have it drilled straight down into the receiver which may be easier. Either way its gonna require someone who knows WTF they are doing.
You can always call LRB and see if they will repair it under a good will repair.