Hi Stoo
I too have managed with an Excel file for a few years. I simply have two new worksheet for every year, one colour, one B+W.
It isn't perfect as I need to try to remember which year I made an image, but somehow I bumble on! A database would be just the ticket, but do not consider the shortcomings of Excel are worth me buying new software.
I think I recall that there is some proprietary software available for this purpose, but sorry to say that I haven't researched further or bookmarked the URL.