...What I have found is that it's not a simple thing to rebuild as this is NOT a regular Mazda Miata transmission! It's a custom housing along with custom internals. This transmission has different blocking ring setup using dual rings for 2nd and 3rd gears...
Not intending to cause thread drift, and perhaps covered somewhere else, but I find it very hard to believe that there is any non-standard Mazda stuff in the transmission. It may not match the US-spec MX5 as to ratios (a guess) but I'd be very surprised if it has any Morgan-specific bits inside. Perhaps take some good pics and post them and a description over on the MX5 forum and see what you can learn.
