Hello, the size of bridges Mim is it identical to Us? (Classic 50s)
Good Sunday to all

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Sorry for my english, not good, i am of the country of Molière, Hugo, Zola ...

Many Mexican models use metric bridges (like the MIM Standards), but the MIM Classic Series bridges have the same dimensions as the American Vintage Reissue bridges. The bridge assemblies are interchangeable as are all the individual parts of both bridges -- you could replace the whole Classic bridge with an AVRI bridge, or replace the Classic's full-size zinc block with a steel AVRI block. (Other manufacturers' vintage-spec bridges and parts will also fit.)

Functionally/tonally, the only real difference between the MIM Classic bridges and the AVRI bridges are the zinc blocks vs steel blocks. The edges of the AVRI bridgeplate are polished more nicely, the AVRI saddles have better plating, and the bottom surface of the MIM Classic bridgeplates often have a ridge/burr at the transition from the rear lip to the flat area. The front bottom bevel and mounting holes on the MIM Classic bridgeplate are actually better than the AVRI bridgeplates, so if you file/sand the bottom of the Classic bridgeplate flat and replace the zinc block with a steel block you'll have a bridge that's just as good as the AVRI for less money than replacing the whole assembly.

edited to add: the newest AVRI saddles have longer string slots (like the original vintage saddles and like Callaham saddles), so the plain strings no longer hit the saddle slot on their way down to the bridgeplate -- the MIM Classic saddles are like the older AVRI saddles. But I don't know if Fender is including the new saddles with replacement AVRI bridges yet (and even if they are, many vendors will still have the older AVRI bridges in stock).