First welcome to the site - we hope that it meets you concours related needs for your project or restoration
The car is a 11/69 Dearborn 351 cleveland built car. ...................
So the bay should be semi gloss black with slop gray hood hinge,shock mount?
No. Hood hinges and springs would have been phosphate and oil as were the front upper shock mounts.
There are a number of unrestored 70 Dearborn threads that will/should help with these generic details for that plant. Don't have to be the exact same engine combination for these details.
Hood latch support and a handful of other parts were a slop gray. Check the FAQs for this section for a list of those parts.
What air filter housing do they have? like how many holes are in the side of the housing for pipes or are just blocked off.
If you would include where your car was delivered to we can narrow down the answer to those questions
What oil cap on rocker cover would it have?
Large flat "cookie cutter" style breather with a plastic hose nipple attached
I have some right rocker covers for it.
Is this the right OK stamp for a Dearborn engine?
You sure that bottom one is correct? Formed differently from the other and from others I have pictures of
Dearborn engines were built at the same place as they were for the other two plants so in this case the car assembly plant does not matter in this detail
Three different styles/layouts were used during 70 production from what I have. Most of the time I've found it on the passenger side valve cover and only on a couple on the drivers side. Is this from the original valve covers or ones you've purchased?