What are the date codes on the head and block?

Yes, it was not uncommon for a block/head cast near the end of an earlier year being used in the next year.

What is the engine serial number (or engine ID) pressed into the block in the ledge to the rear of where the distributor goes into the block?

No 216 engines were painted blue. The Filling Station supposedly has the darker gray engine color that some people say was used on all 216 engines and on 235 truck engines prior to 1954 (some say that same color was also used on 235 truck engines from 1954 onwards).

The true shade of gray for all 235 truck engine colors (53 and earlier and 54 and later) can be argued as much (and as fruitlessly) as arguing which Christian religion is the one true Christian religion (or, which Muslim religion is the one true Muslim religion).

1953 (and later) 235 car engines were painted blue (Blue Flame Six)