Well, if you haven't shot you Mach 4 in 10 years you're probably looking at sinking $100 bucks in it. If it hasn't been shot it still probably needs new cable, string, limb pocket greasing etc etc. At least if it were mine it would. And since this is the hunt of a lifetime, you'll go through another string before next Sept. You really shouldn't go off on a trip like that without a "BACK UP". So, unless you have another Mach 10 laying around you probably should look into a moderate priced finger bow. Yup, everything today is probably faster and quieter than your Mach 4 that's 10 plus years old. They're definitely lighter.

Evidently you're not a true bow junkie, so I would take that Mach 4 to a good proshop for a good overhaul as a minimum.