My quick tell-tale are the '3's,
If they're round on top like this, they're from the Moldvay sets:
Attachment:
IMG_3013.jpg
If the 3s have flat tops like like, the later Mentzer sets:
Attachment:
IMG_3014.jpg
The other clue are the d10s, the more round-tips are from Moldvay sets, the pointy d10s are from Mentzer sets. So based on your pic, I'd guess yes to a 1981 set, but also look at the 3s.
I draw the line at collecting... D&D beach towels.
Shoulda been: ".. from Pangreenia to Floratopolis, from mystical Treeonia of spectral Forests to Schruborial dimensions." - The Forests of Leng