1987 Mark 1b MR2 wont start

Me and my buddies just bought a 1987 Mark 1b MR2 and it started when we
bought it from the guy about a week ago. At the time the battery was dead
so we started it by hooking it straight up to another car, but today when we
went to change the battery we accidentally hooked the battery up backwards
at first. We realized what we did and switched the terminals. After that we
tried to start it and nothing, no sounds, nothing. we tested the battery and it
is near perfect, we even tried to start it when it was hooked directly up to
another car. Is it possible we blew a fuse or some other part? We aren't sure
where to look next. Anything will help