There is the school of thought that an older, or yound depending upon reference, Madiera can benefit from several hours of airtime immediately upon opening. I wonder how it would be if you ventured back now for another sample.
I always wonder why more places do not have older madiera around. This is something you can pour by the glass for a couple of years if it takes that long to finish the bottle with no problems or detriment to the wine as long as it is capped.

Jay.