Doesn't look like it. According to LPB's link, the FX59 wasn't released until 1990, and it's predecessor wasn't available until 1986. Outside of time travel, that pretty much rules out Kill 'Em All. I suppose Peace Sells... is possible, but I was always under the impression that Dave's sound on that record is a JCM800 2203 (possibly boosted) while Chris used a Rockman into a JCM 800.