1951-54 heater cores have different inlet and outlet piping than 1955-56 and will not interchange

The engine is not easily accessible for a photo but definitely had remnants of red paint with no other color present.
It was installed in a 22nd Series Custom 8 that had been renumbered with the 1949 serial number 2252-9-7023 from an original number of 2252-7114. The original Washington State title showed the engine number as G609044C which would be consistent with mid 1948 production.
There is a raised pad at the top of the block just to the rear of the oil filler tube for the serial number and it is blank for the replacement engine. Casting date on this engine is January 24, 1950, so much later than the original.

The red painted engines were not factory rebuilt but rather new replacement long blocks with no stamped serial number.
I have one of these that came out of a 22nd Series Custom 8 sedan.

The "Packard Tips" articles appeared in the Pacific NW newsletter for many years and was written br Gary Russell of Delta, BC. They were consolidated in the book and re-published.
He also ran very well organized annual club tours for many years.

Craftsman 1-3/4" 12 point socket, 3/4" drive with S-K 47153 breaker bar needs 4-1/8'' or more clearance to slip in place. Not a lot of room to swing the handle from above but may work OK from below. Was not able to check on my 1948 Custom as it is put away for the winter but have a spare motor for reference.
Plenty of room in the vibration damper for the unaltered socket.

The bulb chart in the owners manual is incorrect
The rear bulbs should be 1154 or equivalent, same as the front

The rebuild kit from Then and Now Automotive includes the spring.

Then and Now Automotive

AC pump 856138 is a Series F for 1932-35 Buick models 60-80-90

The AC pump for 1937-38 Packard Super 8 is number 152 3196, also Series F and uses the same rebuild kit as the Buick
Earlier 1933 to 1936 Packard models also used the same rebuild kit

Usually the only difference between the same AC Series pump type for different makes is just the rocker arm.
Then and Now may be able to tell you if rocker arm 856211 is correct for the Packard

I was referring to the cover on the smaller shaft which still appears to be incorrect, wrong shape, inside diameter too big for the shaft and has a non-Packard part number on it.

The one with the larger shaft diameter is for the Custom 8 356 engine which has a different clutch disc and pilot bearing.
The smaller one is for the 288 and 327 engines but the cover plate that is with it appears to be incorrect with only 4 mounting bolts instead of 6.

Our supplier did a computer scan as well but then made final adjustments manually with spot samples to get an exact match.