Hello, Mo!
I guess I am still trying to figure out what you are doing, here. Are you actually calibrating instruments at your facility according to the mfg. procedures? Or, are you having instruments calibrated at the mfg. facility using their own procedure? Who is actually doing the calibration?
Stijloor offers one good viable option. If you are doing the calibration work and you have a high degree of confidence nothing will ever need to deviate from that procedure, then that method will work (and that may entirely be the case).
However, if (and this is all dependent on how you write your procedures) you list which standards to use, possible have a limited range outside the mfg. range, etc., then you may end of with a revised document. That case, you might want to approach it a little different. You could still do it in a manner similar to how Stijloor suggested.
Too, I've seen a lot of mfg. calibration procedures. Some of them were pretty good; some of them were quite odd. We would perform calibration in a manner more in-line with how we were using the piece of equipment.