Sunny,
Drilling a hole through the ball to put a pin through it to hold the mast in place would also prevent the mast from swiveling, so that is a bad idea. The mast chord length (distance from front edge to trailing edge) is long enough that the mast cannot be put on the ball without turning it sideways before lifting it off the beams, so it has to swivel on the ball even as it is being raised (unless you want to rig it like a Taipan 4.9 or A cat from the front of the boat which you don't). I will not tell you to lift it with some force holding the mast butt against the ball (since you asked us not to) but that is how all the other Mystere 4.3 owners rig the boats and they also de-rig them by keeping a little downward pressure on the mast as they lower the mast and rotate it as it gets close to horizontal. It is very easy to do and becomes natural to you with a few iterations. You will even learn not to stand too far back on the tramp as you do this so that the boat does not pivot back (bows up) as you exceed the balance point at the back end of the keels (keeping the cat tracks there prevents that also). Something is wrong if you don't do that a few times just like dropping the mast the first time you rig it or take it down. That not only speeds up the learning curve but it also aids retention!
If you feel compelled to do something else, here is my suggestion: install an eye strap in the center of the front of the mast close to the bottom just above the bottom casting. Then tie a line from there to the base of the mast to keep the mast from slipping off. This allows the mast to pivot as needed but you really should try to get used to the other method before doing this as it is worse than the other method for several reasons.
Make sure you take advantage of what Mike Teets wrote earlier - read through the Mystere 4.3 owners' website. There is much useful info there so it will take a while but will be worth your time and Mike maintains that voluntarily for your benefit. If you do not find the info there then you can always ask other owners for the tips you need to better enjoy your boat. You have already proven yourself to be a little smarter than most boat owners!
Mike Fahle
