I am no expert when it comes to wheellocks, but I built a successful one using a great little book by Georg Fauber called "How to Build your own wheellock rifle or pistol". It took me a month of 10 - 12 hour days to make the lock, cutting each piece with saw and file and turning the screws on a small home-made lathe built by my dad. But the springs, especially the dog spring (subject of this thread) and the mainspring, are heavy strong springs. The dog spring in particular puts a lot of pressure on the foot of the dog, pressing the pyrite down hard on the wheel. Even so, my pistol does not work well with pyrite, a weak spark at best, so I made a second wheel with no cross cuts. On this wheel, I use a piece of flint, and it produces lots of sparks making the pistol work fine almost every time. I have read that on original locks, the wheel was rotated 7/8 of a turn to engage the sear, and that the dog was forced upon the already spinning wheel when the trigger was pulled, and the pan cover kicked out of the way. I have watched videos of a polish wheellock maker whose name escapes me, and his locks throw sparks like a cutting torch, but his springs are powderful and thick.
In the case of the lock in question here, I would suggest that the dog spring be heated red, spread to increase initial load,, re-hardened and re-tempered. the only thing that remains is whether the coil mainspring has enough strength to keep the wheel revolving against the tension of the dog.
With a lock like this, it would be easy to run into a complete re-build which is a huge job, and an uncertain outcome.
Here's a few images of the lock I made...compare the spring weight to those of the subject lock.
With deference to William, I agree that flint is a poor choice because of the wear it puts on the wheel, but this pistol has been used so little, and hasn't much worry from overuse in the future, the flint and wheel will work out just fine.
