Hy DFoote, welcome, as EdPruss has said your brake wheel cylinders may be able to be identified using the casting numbers. As to the truck model, look around on the cab firewall and the door posts for the body serial number plate, also look at the engine to the rear of the distributor for the engine serial number stamped into the block, on GMC engines the first three digits of the engine serial number represent the engines cubic inch displacement or size. As to the hoist, again look around scrape and clean the surfaces of the mechanism where and around where the p.t.o. driveshaft enters the mechanism, you are looking for some kind of a plate or stamped numbers to identify the manufacturer of the hoist. If you could provide us with a lot more pictures someone here may recognize the hoist component manufacturer, hope that helps.
