I have no idea who marketed them as Agri power.
Bart, where are you ?? are you the Bart from Belgium, or another Bart ??? I've heard about Agri power in the U.S. before, so you're in the U.S ??
Well the haybine... A 2.40 disc mower-conditioner is usually driven by 80 hp over here.... But that's different to a sickle bar mower with conditioner, as sickle bars cant make the working speed of a disc mower, and dont require much hp to spin the mass either.
With these 5211 you might want to check the water pump bearings for play, (grab the fan and see if you can move the shaft) and the master cylinders of clutch and brakes, for leaks. If they blow, replace the PAL cylinders by Fragokov ones, PAL screwed things up in the 80's so
Zetor nowadays orders them from Fragokov, which last 5 times as long.
A water pump is about 100 Euro, and a master cylinder is 50 to 70 Euro. P.S. dont try the master cylinder repair kits, because they dont solve the problem, they give you new seals and piston, but the actual problem is the bad inner coating inside the liner of the cylinder.