We went ahead and bought the recommended replacement for the Trimark 650 latch, the 1650 that comes with a steel mechanism instead of the Play-Doh one.
We are currently engaged in attempting to make the swap. We've got the new one in, everything fits, EXCEPT...the deadbolt handle won't turn. It's because the new one has a bunch of loops for the latching arm where the old one only had one loop. WHY???? WHYYYYY????
There's only so much room in the cutout, and not enough to accomodate this new structure.
Can anyone advise? Hopefully tonight...we don't want to leave it unlocked!