The serial can’t start with an 8, no Hesalite crystal Speedmaster Pro or Pre Moon does so as noted above you are likely missing a leading 4 or if it were nearly new a 7.
SL was used on dials starting with the 3570.50 model in 1997 (though tritium was used on that model for a year first). The bracelet on the OP watch is earlier than the 1998/849 fitted to the 3570.50. It looks like the 1479/812 maybe which was used on the previous tritium dial 3590.50 so there is indeed a chance it is an early-mid 1990s 3590 model with a dial swap. That is a no-step SL dial as fitted as std post 1997 but the bracelet and likely serial suggest it is earlier. Eugene’s wonderful resource, ILMS has 48.328m dated at 1995...
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