In theory, yes. The pivots/studs (mounted either to the backing plate or brazed onto the fork blades/seat stays) are the same size for all models, but the placement is different depending on the brake model. Most MAFAC centerpulls have a 62mm separation center pivot-to-center pivot, while the longer reach RAIDs (commonly used for 700-to-650B conversions) are 75mm center-to-center. There's an old blog entry that outlines the specifics:
https://ruedatropical.wordpress.com/2009/01/11/mafac-dia-compe-paul-centerpull-brake-specs/
Of the 62mm centerpulls, the Competitions are shorter reach than the Dural Forge/Racer/2000/GT. I have read that it's feasible to braze on the pivot posts for correct 700c brake shoe placement with Competitions, and then switching from Competition to Racer etc. calipers will give you enough reach to use 650B. I haven't confirmed that claim, either with direct observation or with arithmetic; but it's a fun idea.
Rene Herse sells braze-on pivot posts, sized for both MAFACs and their own centerpull brakes:
Peter "the best brakes pull up in the middle" Adler
Berkeley, CA/USA