Sometimes there are old capital assets with transaction history that remain on a set of books but are no longer in possession, for whatever reasons. Some ideas to improve the overall user experience:
1) Ability to show/hide capital assets, or mark them as no longer in possession so they can be filtered out later.
2) Add a drop down filter for show capital assets in possession and not in possession
3)Add a colunn with a disposed of date and the show the date it was disposed of (if any).
I agree with your comment. I have a similar situation where I have a capital asset that is not specifically listed in a class, "for whatever reason" as you describe. I recently sold it, which brings up the issue you mention.