At the top it's stamped 72524 tk. There in good shape tho no corroding or rusting no cracking[/QUOTE
You do what you want, but if it were mine, I would replace those in a heart beat. That part number is Sodium Filled. Do a google search and you will see there is a TON to read about them. They fail and cause very SERIOUS engine damage. It can easily cost 3 grand to fix it.
The valves with the number 75 stamp are solid core.
Seadoo had a lawsuit in regards to the 72 version and no longer use them..
IMO, now is the time as you have the head off...