Help need on really old heating system.

[namsag]

Old system so prob gravity no motorised valves pump only comes on for heating... These usually have an anti gravity valve on CH flow pipe within a couple of feet of the boiler (brass about 3 inches long) they stick in the partially open position which restricts the flow stopping the furthest away rads getting hot .
Can be freed with a experienced wallop with a hammer making sure to support pipe and not hit little scre in middle... Or drain down and replace only cost about a fiver

 

[GHawkins]

picture 1

picture 2

I'll let you tell me what type of system i have.. i don't have a clue. Small header tank connected straight above these pictures. And should all the valves be open? theres one in both pictures.