Its sort of like Leone's rule of what is out of the frame the actors can't see, in this case the rule can be stated as what is not shown doesn't mean something didn't happen.You have to assume that Tuco & Blondie were together enough for Blondie to get to know Tuco's habbits, his style of shooting, the sound and cadence of his shots, etc., etc. During their con games those all had to take place over a period of weeks, later after the double cross when Tuco chases Blondie down he keeps checking the campfires to see how old the trail is each campfire is a night.During the desert sequence for instance what I would think had to be a couple of days was condenced into what 10-15 minutes of screen time.During the wagon ride after the mission, they are covering a lot of time and territory remember when Tuco pulls out the map they have a lot of ground to cover as he describes their treck, that might be a weeks worth of of travel.
ICEMAN is right the knife TUCO has can be seen in the deleted(and just put back in) of TUCO taunting BLONDIE while eating.
A) During shooting, Angel Eyes's name was Sentenze; every time the name Angel Eyes is mentioned, you can see the actors actually saying "Sentenza." After filming, Eastwood came up with the idea to change the name to Angel Eyes.