If you don't want it, put it on Freecycle. Might do somebody a turn. Seems a shame to just bin something leather, assuming there's nothing wrong with it.
Don't chuck it - do you have a website like Freegle beside you? Anything I have surplus to requirements I bung on this site and there are always loads of people wanting what's on offer. Have also received loads of things. Anything to keep articles out of landfill. Freegle is a Yahoo site.
You should offer it to your local amateur dramatical society - they probably put on lots of old-fashioned farces where a suitcase of that sort is an essential part of the plot.