hello @AG Thomas, it looks like you have got a 1965 High Power, normally referred to as "pre T-series", interesting guns, at least to me... could you...
I would rather go for 1965, based on the inverted "5" on the barrel...
@lbmikey is on the right direction, LGK markings on bottom of mag, and serial number 9055, both coincide with pre T-series pistols made in early 60s....
Separate names with a comma.