I will forever be messed up about the blue color because the only 1991 Kona Fire Mountain I ever saw was yellow, not blue.  It was back when I was going to the University of Massachusetts, I had one of three 1992 green Fire Mountain bikes on campus (and oddly all three independently ended up using Scott AT-4 handlebars).  The 1992 had the black plastic thumb shifters rather than the rapidfire shifters, but it also had the horseshoe brake booster and the printing on the saddle was in yellow. 
I test rode 3 bikes in the parking lot of the LBS and said I liked the Kona but wanted the rapidfire shifter for the rear and shop said "we can do that", so I had the 1991 rapidfire shifter for the rear but a thumb shifter for the front.  Still got the bike, same shifter configuration.  I like the friction shift for the front mech because you can fine tune it for whatever gear of the rear cassette you're using.