I have been sorting Spain and realized that I have way more than I thought.
I have done exactly that! Stamps have very much taken a back seat for a while I did bits and pieces of work on our house and my sister's kitchen and did stuff a couple of days every week on the Heritage Railway I volunteer on.
I went through four or five of the shoe box sized boxes of world wide stamps sorted by country into glassines and packets. I usually divide a country's stamps up by era if there are enough to warrant it. I then combined odd packets from each box and put them where I could into boxes for single countries or groups of countries. Very soothing and enjoyable.
But I did discover an astonishing number of middle period and modern stamps from Spain - enough to have to find a box for Spain alone