Merging 401(k) & MP Plans

as we approach restating plan docs, curious if there are thoughts about merging existing 401(k) and separate Money Purchase plans by the same sponsor? My initial reaction for long standing plans is to keep them separate. Though certain fees would be larger as applied to two plans, merging them might be complicated and risk prone.

Any/all of our MP plans were either merged or restated into something else long, long ago.  You have to maintain the accounts separately and keep the J&S annuity provisions on those accounts if the rest of the plan doesn't have them.  Our (FTW) prototypes have a checkbox to indicate if such money exists and it triggers the necessary language in the  SPD and elsewhere.

Ditto/agreed - no reason to keep separate and file separate 5500's, maintain separate documents, etc.