ScalarMaps - adding and removing dataReferences dynamically

hello visad users!

i want to add and remove dataReferences to/from a displayImpl. they all have
the same domain (time) but eventually different ranges (several currencies).
i wonder if there isn't an easier way to achieve this goal, than allways 

a) remove all ScalarMaps and dataReferences
b) add all the previously used Maps
c) add eventually newly needed maps
d) add all the previously used dataReferences
e) add the new dataReferences.

it would be great if somebody could show me an easier way,

thanks in advance,

henner