Conforming mortgage loan limits by county and year
The high-cost area conforming loan limits within the contiguous United States were created by HERA (the Housing and Economic Recovery Act of 2008) and therefore do not exist prior to 2008. For periods prior to the enactment of HERA, just use the historical nationwide conforming limits. There was also a temporary bump to the conforming limits enacted a few months before the passage of HERA, in the Economic Stimulus Act of 2008.

The high-cost areas that you identify (Alaska, Hawaii, Virgin Islands since 1992, and Guam since 2001) had, by statute, high-cost area loan limits that were capped at, and as a result effectively always, 1.5 times the conforming loan limits for the contiguous US states. Somewhat amusingly, the legal text responsible for the cap at 1.5x is actually still in the law; the authority granted to the Director of the FHFA to modify conforming loan limits was just tacked on to the end. You can find this text at 12 USC § 1717(b)(2)(C).