I did a search on Google for "Troy Bilt Horse Service Manual" and may have found a few sites with the free information which you seek. I suggest you do a search for the info you desire. There were also specific sites with info for the carb job for a troy bilt horse, which included schematics.
I did not know what Tecumseh engine you have, which is something you need to know before you try to add that carb. Other than that, the only linkage you should have is for the throttle, the choke and the govenor. Most of the time the govenor is controlled by a spring, the throttle most likely is a cable and the choke will either be a cable or linked.