I'm following your postings with much interest and appreciate you taking the time to post them.
I presently have the head off of my 954 because four of the exhaust valves on cyclinders 1 and 3 were burnt. As a result compression tests were 55, 176, 60 and 176 on cyclinders 1 thru 4. Just replaces all the exhaust valves and lapped all valves waiting for new valve seals since everything is torn apart and the bike has over 46k miles.
I just want to confirm the cam timing fingers on the end of the exhaust valves appear in the correct position and are not potentially flipped around.
Simply laid the cams into the prescribed position, laid a metal ruler over the cam lobes as you did then measured 15mm from the bottom of the ruler to the head surface on each lobe.
Appears to me you are on the right track. I didn't find a spec for the cam chain length to determine if it is worn excessively. If you have one or the Honda fellow knows what it should be then that information is helpful as well.