There've been a few posts mentioning that sleeper passengers are entitled to use Amtrak lounges (where they are offered).

If I do not book all of my segments in sleepers, which segments qualify me for use of the lounge--the arriving ones or the departing ones?

In other words, let's say I'm taking the Capitol Limited from WAS to CHI and the Empire Builder from CHI to SEA. If I upgrade the CL but not the EB, do I qualify? What about the opposite--riding in coach on the CL but departing in a sleeper on the EB?

If I upgrade on-board to a sleeper on the CL to CHI (and am either ending my trip there or continuing on the EB in coach), can I use the lounge there? Would the conductor give me a new ticket indicating that I was a sleeper passenger on that train?