I have a bit of a shameful update for everyone, as I wondered how quickly the coolant filled in the cylinders even with excellent compressions, and went over all my coolant lines again. I still didn't see any problems, until I stumbled across this post:
https://www.s2ki.com/forums/s2000-under-hood-22/help-coolant-cylinders-280321/

Seemed like a decent likelihood I skipped over that so long story short I left the car at Honda for a couple of days to clean out the engine and and give the whole build a once over to make sure everything was done right. Picked it up yesterday and it is running and sounding absolutely beautiful, Honda ran a leak down and compression test and said it passed with flying colors. My service advisor personally put 53 miles on it to "verify" it was running good, but what I heard from one of the shop hands was that he decided to take my car home for a night! Either way, I am finally able to enjoy my car and have a lot of work planned for it in the future, starting with a new set of seats being swapped in as I speak.

 

I think I would change the oil, even if you did it right after the incident I would do it again. Oil is cheap and no sense risking any extra wear due to diluted oil.

 

the Honda dealer changed the oil twice, once immediately following and again after putting 53 miles on it

 

Really pleased for you mate about time you had some luck..

 

Great news. Now you can enjoy that lovely car.

 

Just thought I'd provide an update to everyone that after a couple weeks of driving, I've had absolutely no problems with the engine swap whatsoever and the car is running, driving, and handling beautifully. The P.O. had a set of brand new 225's mounted on all four wheels, which isn't a staggered setup and I wasn't happy with the condition of the stock wheels. I purchased a set of SSR Integral GT1's with 225/245 Bridgestone Potenza S-03 tires for only $400. Also swapped in a very clean rip free set of seats.

 

congrats! hope you're enjoying the car.

 

Glad it ended up right side up. I like the wheels. Very nice.

 

Congrats, looks great.

 

What a journey! Glad to see you have much persistence and did not give up on troubleshooting. I hope you are able to enjoy the S for many years to come.