Vera, Vera Vera.... please don't tell us you bought a boat sight unseen???
That's a lot of boat. Actually the gear shown in the pics looks better than I'd expect, and it looks like this boat was well equipped at some point. How does the interior look? Did you have it surveyed and are you sure that it's otherwise seaworthy??
First, have you searched every nook and cranny and certain the missing parts are indeed not there? if so then you've got some (expensive) shopping to do. Hopefully the supplies are nearby.
This site Harken
should help you figure out what you'd need to find. This is good gear but expensive, you may get away with similar configurations with a bit less expense, but this stuff works real well. At any rate the pictures should help. You should check out the Mainsheet systems section. You'll need to know how big your sails are so some measurements will need to be made (can't find data for your boat on line)
You'll need mainsheet tackle for both the main and mizzen booms by the look of it, and ideally a vang, esp for the mainsail.
Good luck... maybe you'll find the bits somewhere...