Oh Boy, looks like a bad head gasket 2.7

Hi everyone, this is my first post but just let me say that the info I've gained here has literally been invaluable! Thank you all so much!

I picked up / traded for a 2001 4door Prerunner 2.7 with about 167k miles. Had a old GMC C3500 that i used as a tow vehicle for my offshore boat. Did it's job well but I no longer have the boat and that big boy wasn't getting much use.

The Prerunner looked to be in good shape, and I need something to make short sub 200 mile trips about once a month. When i got under it, I was very surprised! Not a single leak anywhere. So I treated it as a project and started replacing everything that I thought was a possible liability. You name it, it was probably replaced with an OEM Toyota part.

So about 2 weeks ago after a 500 mile turn around trip, I noticed some difficulty starting it. Where before, it took about 1-2 cranks and it fired and idled nicely, now it took longer / multiple cranks to start it and it would run rough for 5-10 seconds then smooth out. This was random and would only do it maybe 1/every 10 times. Changed the plugs and it got better but after a week the random starting issues persisted.

I started thinking fuel delivery, spark, timing?? But my gut told me it's probably a head gasket. So I checked the dipstick, oil is still brand spanking new, clear amber no sign of water contamination after 1k miles. Took the radiator cap off when cold, fired it up (really struggled to get her going this time). After multiple tries, she ran, no stutter 1700 rpm idle gradually lowering to 1k rpm. Temp gauge showed warm after a couple of minutes but it took like 15 minutes before the thermostat finally opened. There it was... I see a little mist wafting out of the filler neck on the radiator... put my nose to it and there was, a very strong smell of Gasoline! I'll put the combustion leak detector on it and see if the purple fluid turns yellow or green. I'm 99% sure it will.

Probably gonna go with the OEM Toyota head gasket kit. The dealer has it for $269, and some new head bolts. I NEVER EVER use the same head bolts twice, don't care if it's a Chevy or a Mercedes. I figure cheap insurance.

If you are still reading this novel, God Bless You... Lol. Had to give you as many details as I could.

My main questions were

1. Seeing as I'm not sure it is the original engine, it looks pretty new with no leaks and no oil or grease caked on the block itself. Even the block paint looks original black and clean, does not look repainted. The oil pan looks new, the timing chain cover looks new and I could tell the oil pump has been off (some of the phillips screws are a bit beaten up. Even the damn freeze plugs look clean...and in 3k miles, it has burned zero oil. It looks like the head has been redone due to the red / orange RTV i'm seeing all over the place. I'm thinking it may be a JDM motor.
Previous owner has no clue, got the truck from a relative in trade....Whatever
Should I replace the entire engine with a zero miles engine (rebuilt) Or should I just do the head? I'm leaning towards just the head depending on what i find when i lift it off of the block. Would love to get some input.

2. I'm in the greater Los Angeles area / Pasadena area. But I will gladly drive further out.
Can anyone recommend a machine shop that is good with Toyotas, where i can have the head checked and possibly milled a few thousands for a clean mating surface.
I found a lot of Duralast parts on her and I think they may have gone budget on a few things. Stuff I probably wouldn't have done, I'm almost positive they didn't change out the head bolts. If they stretched beyond spec, this may have contributed to the problem.

NO CODES WERE PRESENT OR SHOWING AT THIS POINT. All of the live data from my scanner shows everything working up to spec.

Parts changed out 3k miles ago prior to having ANY Issues of any sort, I changed them because I didn't know their condition, were not as expensive as I thought they would be and i figured peace of mind was worth it. Here are a few of the things I've changed.

1. The entire cooling system, if coolant goes thru it, it was replaced with factory Toyota parts from Longo Toyota. Plus new Toyota Red Coolant with Distilled H2O. Plus the belts / hoses.
2. Fuel pump, screen, filter, check valve on gas tank & fuel pressure regulator.
3. Spark plugs

Thank you for taking the time to read all of this, appreciate any feedback.