Like Bern said... no spill timing on the rotary pumps. They are what they are. Probably the biggest thing about them is setting the position of the cam ring such that it properly limits maximum delivery. That can be done on the tractor most times tho... if necessary. It's easy with a dyno. It could be done within a reasonable margin of error just by observing smoke and usable power if you know the tractor well enough. Not something I'd really recomend tho, really... for all it costs to get a DB pump serviced.
John would also be the one to give you all of the specifics on rebuilding those pumps.... I really don't mess with them much myself.