Rankin Park Plaque Multi Multi-Cache

Everytime I go by here, I think of how this would be a great spot for a geocache. It is too close to others, so I made it a multi. 

Final Cache is about a mile away. You can find it using the plaque, and the related web page. 

The final is at: N 38° 00.ABC W 122° 07.DEF.

AB: The plaque was dedicated on June 4, 19AB.

C: The amount of horseshoes at the base,   -4=C

D: Region Number,   +2=D

E: The number of letters and apostrophe in the full name of C.S.H.A. (hint: the h stands for 10 total) (see related webpage.) divided by 18.

F: The amount of letters in the last name of the person the plaque is dedicated to.

Once you figure out the numbers, the cache should be wherre the coordinates take you. 

*Bring your own pen(cil)*

Please do not disturb the nearby residents.  

Congratulations to donvsop and Alamogul for the FTF!

You can validate your puzzle solution with certitude.