Hello, I am amateur woodworker and would be interested in taking any spare square nails off your hands. Any size will work, as long as the are straight. Please message to my inbox if interested, thanks.
You can still buy cut nails at the hardware. However if you're interested in creating a period reproduction old nails might be best. These nails can also be used to date old sites. Many nails had rosettes on the heads identifying their maker sort of like a hallmark. I don't have any on hand but I'll keep you in mind if I get any.
I noticed this was your very first post - so, Welcome Aboard Someone123! Take a look at Forum:
Massachusetts for information (i.e., clubs, etc.) directly related to your state.