My good buddy is a Defender fan, and there are myriad possibilities for the identity of the one you saw.
In the 90s, there was a four door North American Defender with the external roll cage. About 500 imported, before they stopped US Defender sales. But I think all of these were white.
Many companies, Arkonik, HImalaya, East Coast Defender, and others will sell you a pre 1995 ROW (rest of the world) Defender, which is legal to import now, that has been modified and tricked out. My buddy has an 80s four door Defender built by East Coast Defender, with basically everything new. A Chevy V8 and an six speed auto. New leather, front and rear AC etc. He paid 125k about 4-5 years ago and then sold it during COVID for significantly more. These would be not CARB compliant I bet, hence the Montana tag. My buddy was living here in FL when he bought his.
What you saw MIGHT have been a ROW Final Edition Defender, but it would have to come into the US under "show and display" rules, which limit you to 2500 miles per year. Some Porsche 959 came in this way.