I wonder if these days if Pandora/Stephanie has ever been asked personally to consider getting huge boobs again and making a comeback?
I strongly doubt she wants to be back in the business; besides, she is 60 years old now and your priorities change as you get older. 
What I have learned over the years is, that if they are going for implants most likely for themselves to enjoy them for own pleasure and not for a business plan, they might leave them in as long as possible, but if it is only because of the money or if they where forced into having them. They might remove them as fast as possible when things are over.
my2cent
I second that; fame and fortune means gone when they no longer serve a purpose; personal desires means they have no intention of parting with their implants. We can also see that attitude with girls that had problems but don't want to part with their implants, girls like Brittany and Lilly.
The decision for removing them or live with them might also be even more complex.
Like what is your family or friends saying or reacting about them, what does the personal environment say about having them, have friends with implants make it easier to get a decision in one direction, how are the job chances or what say the employer. Some women has the fortune to be their own boss and might work from home (Keisha Evans or Chimera Costumes come to my mind) others have to confront with their past (like Crystal Gunns who has problems working in a school cafeteria even after five years past her active career).
I bet a lot of parents did search Crystal on the web immediately after earing who she was in the adult industrie

.
I sometimes find it funny how people react to some things (even if it is only about big boobs), but the adult industry is such a big player with so much different fetishes.
So if there might be no one watching or using all the special toys there are making, then how could this industrie be so big

.?
Sometimes I compare such social reactions with other things, like having people smoking, so beeing in a group of smokers they think smoking is OK and see no problems, even if there might be one non smoker most of them don't understand the reaction of the non smoker, same crosswise when one smokers meets a group non smokers and there are much more examples, like weed in the Netherlands or eating insects in some areas of the world.