UPS lost the cutting fluid I ordered for honing the cylinder. I finally got started today. Honing went really quick, in like 25s it was crosshatched. It brought out some wear marks I couldn't see before. Took half the day to clean off the gaskets and clean the engine block etc. So what do you use to clean carbon off the valves? Other than that it should go back together tomorrow.

With the valves removed, gasoline and or a round wire brush
in a drill motor will remove carbon real quick.  Brake cleaner/carb cleaner will work as well.
 
Once done and the head assembled, flip it upside down (spark plug installed) and
fill with say Seafoam.  If the valves are leaking (over night), you'll see the Seafoam go 
past the valve seats and come out the ports...
 
If so, some valve seating compound, along with the tool will help seal those up 
fully...
 
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Won't the wire brush damage the valve mating surface? What about the combustion chamber, can the valve seat handle the wire brush?

Just go nice and easy and with a cleaner(gas, brake cleaner, etc), won't hurt anything.
I'm talking a 1/4" shaft brush, used on a hand drill motor-NOT a super heavy duty brush on a large grinder.
 
Works fine on the head, piston, etc.
 
A piston top & block pic(18 HP Briggs) cleaned after 15 years of service. 
Damage is from a dropped valve that destroyed the head and piston
(piston & head WAS replaced due to valve parts impacts).
 

 
 

Another delay. The valve seal I got in the gasket package just falls into place. No resistance. Now I'll have to order another seal and wait :(.

You just have the one seal, on the intake valve, correct (part # Briggs & Stratton 690968
SEAL, Valve ) ?
 
 
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Hey, I'm getting mixed answers for how to orient the piston rings. These are inside beveled rings. Both look identical. Right now I'm seeing videos that say bevel goes up on the first ring and down on the second ring. The guys I bought them from say both go up. First they said both go down.  Can you tell me what the real truth is?
 
Also angles between gaps, seems like there's more than one opinion on that.
 
thanks
 

There should have been directions included with the rings.
 
In any event, look at approx the 15 minute mark below:
https://www.youtube.com/watch?v=4VnNDUOsxEM 
 
The rings (both upper compression rings staggered about 180 (the end gap), from each other, to help with sealing.  You DON'T want them in-line as compression will now blow straight past them.
 
Same for the oil rings. As there's 3, I set mine so the end gaps are about opposite each other BUT 
above / away from where the oil level would be once assembled..
 
A Briggs shop manual specific for your engine would give you what the factory recommends..
 
(I work on most every engine make/model, etc, so having a shop manual for all is not practical....)
 
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There were cryptic directions with the rings. Not very clear. And after getting two answers from them I don't know what to trust.

Also, I had watched the video you referenced yesterday and the rings don't have bevels in that one so I'm still unclear how to orient the bevels.
 
thanks