Things happen in 3's they say. See the post on Motorhome door lock woes.
Is your lock a horizontal or vertical lock? Got a picture?
If it's the vertical lock common to the Classic MOHO we may have a solution. Guy99 has the same problem with broken tabs on the actuator plate, as do I. We may be working up a custom fabrication order for some machine shop to help us out of our broken lock problem.
A word to the wise... Don't pull too hard on the door handle, it may be locked!! You may not know if your lock plate has already broken one of the two tabs that contact the handle. Once you break one the final one is easy to break, then you're out of lock....er luck.
Let us know your lock style. If it's a horizontal handle you'll have to see if you can find one of the more common replacement lock sets.....but be warned ... they 'aint' cheap.