Model is RS125, GC number is 41-621-07
Can't find a manual for that GC number. It must either be very old or could you have written it down wrongly.? Who is the manufacturer as show on the data plate?
Other versions of the Mexico RS125 have an output which can be adjusted between 30kW and 36KW. That is a very high output, unless the house is extremely large or has poor insulation.
Unfortunately installers tended to put in very large boilers to make sure that the customer couldn't complain that the house was too cold. That was OK when gas was cheap and "The Gas Board" had a monopoly.
You can find out what size boiler you really need by using the
Whole House Boiler Size Calculator. You may get a surprise.