Just for clarification, whether or not you individually completed 51% of the construction does not determine whether or not you may receive the Repairman's Certificate for your aircraft. The only time 51% enters the registration cycle is in determining if the majority of the aircraft construction was accomplished by amateur (non-professional, unpaid) builders. I noticed in a different thread you used a builder assist program, things get a little fuzzy sometimes with those programs in regard to the 51% amateur build rule but if the FAA has signed off on the program....whatever.
As long as you are a builder of the aircraft (might even be one of the members of an amateur group build or last of a succession of builders) and can demonstrate to the FAA inspector that you have sufficient knowledge to accomplish the Condition Inspection you should qualify for the Repairman's Certificate. Only one certificate can be issued per aircraft regardless of how many builders were involved in the construction.