Try this:
Take the mountain heights that don’t match between the Map page (p. 56) and Harley's Map (p. 30):
St. Sauveur: 679/678 = 1
Sargent: 1373/1372 = 1
Pemetic: 1248/1240 = 8
Penobscot: 1194/1193 = 1
There is also another "P" mountain, Parkman which doesn't have a height listed = 0
So if SPF pertains to State Plane, Feet, then the state plane coordinate system (SPCS) changed to the metric system in 1983 (SPCS83), but as noted, from time from its inception in 1927 it used feet (SPCS27). The first digits on the camera (p. 19) are 1927
Note the SPCS27 code for Hancock county is 11801 = mountain height differences.
Maine uses the transverse mercator projection. Coordinates in this system are designated as Northing and Easting. The lobsterman (p. 23) is pointing to NORTH and the crab is pointing to EAST. The star code also spells NORTH, and EAST is written in the water on p. 47
To find the coordinates:
P. 17 (which shows the SPF flag) has a green border and a border phrase tells us to use “last in line”. It also tells us it is “one of four”. Take the last letter from the border phrases on the four green border pages and they anagram to “SEE RED, NEXT YELLOW”. This sequence comports with traditional croquet (“tradition carries" border phrase) that pairs red and yellow. Note this is also the color pairing of the compass rose on the map page.
Use the p. 44 road signs to get the numbers and pair the red and yellow signs. P. 7 treasure chest hints to multiply (X) and add (+) to see (C) the coordinates (*).
Red signs:
Add the signs of locations on MDI = 23
Lookout Point 5
Otter Creek 6
W. Tremont 12
Multiply the signs of locations not on MDI = 1054438
York 167
Eastport 82
Lubec 77
Yellow signs
Add the signs of locations on MDI = 46
Somesville 12
Norumbega Mtn. 16
Bass Harbor 18
Multiply the signs of locations not on MDI = 30282
Portland 98
Montreal 309
Pair the added Red MDI signs with the multiplied Yellow non-MDI signs to get the Northing coordinate = 233028.2
Pair the multiplied Red non-MDI signs with the added Yellow MDI signs to get the Easting coordinate =1054438.46
This equates to GPS coordinates 44.3056552, -68.2318619 or 44d 18M 20.3586S, -68d 13M 54.7027S
This puts you just off the Day Mountain Trail.
Use the Key page (11) to verify:
There is a map section in the lower left showing Otter Creek and the Park Loop Road. It is the only section like this that has arrows and also the word “WAY.” If you follow the arrows it points the way you would go to get to Day Mountain. The red arrow in the Big Dipper constellation points to it as does the yellow flag on the ship in the upper right corner.
There are
5 pointed stars in the Big Dipper illustration, there are
3 stars outside the constellation, add them together to get
8 = 583 = the height of Day Mountain.
This also follows a Fibonacci sequence: “count to (two) three” = 1+2 = 3, 2+3 = 5, 3+5 = 8. Fandango is a 3-step dance and in the 3 steps of a Fibonacci sequence you get the numbers for the height of Day Mountain (583).
Wabanaki, the native people of Maine and hinted at by Chief Abnaki on p. 32, translates to "people of the dawn" = begin at Day.
Happy hunting!