hi Mark and welcome aboard.
I'm not sure if the mods would agree, but this question seems to be on- topic for the main board, where we would most likely have more board discussion.
With 100's of us fellow cardboard nuts, I will bet there are also 100's of individual methods for tracking our collections.
I use a basic spreadsheet which serves mainly as a checklist. It still hasn't prevented me from buying something I already have...but hey, if one is good, two must be better
I would like to hear of some other methods used, ( fancy software, back of napkins, databases etc.)
( Leon, et. al...maybe this is main board worthy?)