just about any watch bracelet will stretch over time due to wear and tear, caused by a number of factors I.e. perspiration, being heated and cooled from being worn, knocked around, the Spring bars suffering from stress due to this.. even if you simply push papers around, it might slow down the inevitable.
there is a gentleman in HK who is renowned in the watch community who restores Rolex bracelets exceptionally well. his name is Michael Young. see here:
if bracelet stretch is simply your worth (PS I don't own a sub or sub c) then getting the sub you like and getting the bracelet repaired can now be the viable option.
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