You need to post some photos or nobody can help. It is likely either the original "round-back" type or the later "square-back" type. You car was originally wired for a 1-wire regulator, but that could have been changed. Both types of alternators could have been wired for either a 1-wire or 2-wire field. You might even have a later model alternator. You definitely want to upgrade to an electronic regulator either way, and both 1 and 2-wire types exist. I have never heard definitively that the regulator needed depends on the output rating of the alternator, i.e. that the max field current varies much between them.
As mentioned, it is easy to determine whether the un-mentioned problem is in your alternator or regulator.