Nice Electra, I too feel they are very under rated bikes. I owned one & my father also owned one, used to go 2 up with my mom all over the place.
The Electra's came out in Jan. of 1963 and ended in August of 1965.
from 1/63 - 7/63 650 was the last serial number
from 7/63 - 9/64 6201 was the last serial number
from 9/64 - 8-65 7961 was the last serial number
so your serial number starts with "EL" for Electra , and based on the serial number, looks lie you own a 1965 Electra.
As you may have noticed, the Electra uses primarily Wipac electrics except for the starter (Lucas) & turn signals (Hella). The Electra came with two "Grip tip" indicators which were made by Hella, also known as "bar end winkers", or "ox eyes". These were most common on BMW motorcycles of this era. I had them on my Electra & my slash two BMW & I like them a lot, as they each have a forward & rearward facing lens, so you only need 2 indicators to give 4 way viewing, and they don't vibrate like the Lucas stalks. They are still available as genuine Hella, or you can buy oriental copies.
This was a model produced for the American market, so that Berliner could attempt to compete with the Japanese bikes. The Electra had a new gearbox, electric starter (Lucas M#), 12 volt electrics (two 6 volt batteries) , high output alternator. and turn signals.
The frame was similar to the Navigator, and had the Norton heavy twin rear brake drum laced to an 18" wheel.
Top speed in "Motor Cycle" magazine test in 1964 was 83 mph.
Some info from the NOC site:
http://www.nortonownersclub.org/history/lightweight
I have some Electra parts available. If you need anything PM me.