IO75

hello everyone I'm trying to fix my pool cleaning system (don't know the history about it since i bought the house a year ago) and i opened the valve just to find that is empty, no gears or nothing inside , and where the pop up heads are they replace them with a plastic cover . i think the system couldn't be cancel since these are the only returns to the pool. the thing is that I'm about to re plaster my pool and i think would be the perfect time to install new pop up heads, now my questions are: -can i fix my current valve and install new pop up heads even if they are a different brand? (i was trying to find my valve brand but i don't see it, I'll attach a picture) -or i need to replace everything , valve and heads? all i know is a top feed valve with 4 ports in the bottom and 4 cancelled heads in the pool. thanks in advance.I'll really appreciate any suggestions https://drive.google.com/file/d/0B0wP_Pqibm3bVklRY0VuY2ZNTWJCVV9YRDlsOF96Z21Nb184/view?usp=drive_web

hello everyone I know this is an old thread but I'll really appreciate any suggestions I'm trying to fix my pool cleaning system (don't know the history about it since i bought the house a year ago) and i opened the valve just to find that is empty, no gears or nothing inside , and where the pop up heads are they replace them with a plastic cover . i think the system couldn't be cancel since these are the only returns to the pool. the thing is that I'm about to re plaster my pool and i think would be the perfect time to install new pop up heads, now my questions are: -can i fix my current valve and install new pop up heads even if they are a different brand? (i was trying to find my valve brand but i don't see it, I'll attach a picture) -or i need to replace everything , valve and heads? all i know is a top feed valve with 4 ports in the bottom and 4 cancelled heads in the pool. thanks in advance. https://drive.google.com/file/d/0B0wP_Pqibm3bVklRY0VuY2ZNTWJCVV9YRDlsOF96Z21Nb184/view?usp=drive_web