The picture on the left shows the top of your radiator and the surge tank. The cap is on the surge tank. You have a steam line running from the top of the radiator to the surge tank, and the radiator hose running from the engine. Check the core condition by screwing out the fitting for the steam line and looking in there with a light.
The middle picture is of the surge tank. If you look toward the bottom of the picture, on the right side of the surge tank, is a sight glass for your coolant level. When cold, the level should be even in that sight glass.
The right picture shows the lower radiator hose, drain petcock, and what I believe is one of your trans cooler lines. Drain the system with the petcock. Hopefully it will move easy for you but you might need to put a pliers on it. It also looks like there is a nipple on the petcock that you can attach a hose to and have it drain out with very little mess.