The problem is everybody selling a steel Colnago advertises it as a Master or a Mexico because those fetch the most money.
The Master feels stiffer than a Superissimo but I doubt that it is and if you pardon the heresy the Superissimo is a more comfortable ride not that there is much in it.
Yours has a tang under the top tube for a race number so good chance it was built for a pro race team.
ps you don't need to be lightweight and fit to enjoy a great Italian racing bike!
The Master feels stiffer than a Superissimo but I doubt that it is and if you pardon the heresy the Superissimo is a more comfortable ride not that there is much in it.
Yours has a tang under the top tube for a race number so good chance it was built for a pro race team.
ps you don't need to be lightweight and fit to enjoy a great Italian racing bike!