I would finish the square piece with the hole drilled through it and use it as a prop for taking photographs of pens with. The grain in that piece is to pretty to throw away.
I would use the round top piece as a pen stand. The problem with wood like that it looks so much nicer as a whole because you see more of it. When we cut it into small little round objects it losses its character. It will finish nice but not nearly as it does in that original state.
Very good approach to recycling beautiful wood. I found a birds eye maple table top in the trash once and I thought I hit pay-dirt... needless to say it was a 1/4" veneer that really looked like a solid piece. Looking at the blanks you have already turned, you will make some VERY handsome turnings with that $5 find... Good luck!
I did some bolt actions with wood from a German 7mm mauser from WWI they were a big hit with the history. The stock was given to me by a gunsmith who rebuilt the action into something else.