Jim, as you know, I have worked with the researcher on Dumps. If there is no service record for him with the Union navy, might there be some rosters or muster rolls for the "Rodolph" that would indicate an enlistment date and place? I will admit to never having looked into Union navy service records so do not know what, if anything, is available. I guess this is a long way of saying I have no good suggestions on where to look.