Allis H4 hydraulic control block

yep the valves are a stacked body of individual valves with "O" rings between the sections , also "O" rings in valve body - can replace just the rings and get good results or buy a kit for 3 times the price and get the same rings . 

Although I am not familiar with this particular set-up, most hydraulic components are fairly easy to work on. Safety is key. Oil under pressure hurts. Relieve all pressure by working valves after shutting down energy source. As the man says, take pics if you aren't sure. Another important point: buy a good set of seal picks. They usually come in sets of four, with different angles/shapes of points and hooks. Be very cautious of not scoring or scratching any surfaces. Valve bodies are pretty straight forward, and although there may be a spring or two, if you are careful, parts won't fly too far. Watch for the tiny ball bearings used under some springs (relief valves). Keep it clean! Disassemble on bench covered with a rag. It keeps things from rolling around. Keep it clean! Wash your hands, tools and parts twice before re-assembly. You don't want to do all that work only to find the spool jams on a piece of dirt, then scores the bore as it moves. Sorry for the long post, but I've seen too many good jobs go bad just because the mech wasn't as anal as I am.

It's always nice when a plan falls together