JMO, but for short term use like a vacation or special occasion, the better way is to rent a rig. It isn't cheap these days, but a better way to go if you need something quickly -- particularly if you will not be working on it. The other way is to buy a new rig from a reputable dealer, and use it briefly while in reach of the dealer. Your rebuilt may be a good one, but need some testing and tinker time to know -- and might act up when you want to use it for a few days, or not be up to Uncle Charlie's critical eye.
exhaust nasties in the leg are normal, but can indicate something about condition -- maybe rich running if a PO was running it that way for break in. Shavings in the l.u. can be questionable (but often normal), and stalling or other running issues on a used or rebuilt motor would need to be addressed -- may be operator handbook issues, or something to be fixed. You can rent or borrow a compression tester to check the overall condition of the motor (look for compression to be roughly equal between cylinders), and I would do that if you are going to try to prep the motor at all. Permanent tanks are a problem in a boat that has not been used regularly (water and other contamination). The remedy is emptying and cleaning, and probably installing a water separating filter. All normal stuff, but have to get up close and personal or pay somebody do it.
I would get Uncle Charlie to go halvies on a rental.
