I've got one of the mortice locks and the skeleton key on our TT. I don't bother to lock it since all five of the sliding windows can be readily opened from the outside. It works, though.
I've had two houses with antique locks that used 'skeleton' keys. I scrounge old 'rim locks' whenever available (free), and I've even been known to pay for one. These old locks are bone-jarringly simple inside. Take your TT's lock out of the door and disassemble it. I doubt things will sproing out into never-never land (like they can from a sailboat winch or a bicycle in-hub gear). Clean it, lubricate it, replace the springs if needed, stuff it all back together. I'll bet that the 'bolts' - the two bits that travel out to grab the 'strike' on the jamb when the key is turned - are the pieces most likely to have been damaged (by slamming a door shut with the lock already locked); probably would not be all that difficult to make new ones, weld/braze the broken pieces.
For encouragement: 7-19th c rim locks restored, Bennington knobs reglued as necessary, 6 new strikes made of angle iron, ready for paint. Two new brass strikes for fancier doors: brass from McMaster-Carr (old strikes on the right had been badly modified), ready for clear coat. Mortices in both the brass and the steel strikes were cut with a Dremel and carbide bit.