As others have stated, they are not worth saving as an investment. You might or might not be able to sell them for a tiny profit now. Some are successful at this, while others aren't. Its a tiny profit and not worth the time and trouble IMO, unless you have the ability to both find and have a ready market to sell hundreds at a time.
Your 's' Ike might be 40% silver. All 40% Ikes have an 's' mintmark, but not all Ike's with 's' mintmarks are silver.
I typically use what few clad Ikes I come across for tipping purposes. Servers generally seem to like them, and some younger servers have never seen one before.