CTG stands for cartridge.
ctg: cartridge
Cartridge
Without serial number, between 1966 & 1988.
2k What is this value based on
50-500 usd
1969 value guesstimate around $450
No more than 225 USD
400 to 600 dollars depending on condition and where you live.
About $250 in excellent condition.
It stands for the word "cartridge"
Don't know the value, however based on proofhouse.com ,it was made in 1973.
No such sn in the Diamondback series