From my understanding the D130 was in production in 1948 or so and the D130F was introduced in 1963.
I have seen reference on these forums to a serial number in the 25xxx range being from 1957 on a D130. I now have two D130F's with serial numbers in the 18xx and 52xx range. The 18xx is from from a 1965 Fender amp where everything, trannys and tube sheet, dates it to 1965.
So the question is, was there in fact a seperate serial number system for the "F" series speaker originating at JBL or were they serialised at Fender and when did this happen ?
Here is the reference to quoted dates
http://audioheritage.org/vbulletin/s...24&postcount=6