My spreader base was riveted to the mast and was just a wee bit loose. My boat bible, This Old Boat by Don Casey says that rivets holding the spreader base to the mast is not a good approach but was not uncommon on older boats (like my 1978 M-23). Problem is compression loads on the mast tube. So not wanting to make a major mod and sit out more of the sailing season I decided to replace the rivets and roll the dice for one season. I purchased a rivet tool (Arrow) at the Depot and another at Tractor supply. The one from Tractor Supply did two SS rivets before cracking in half and the one from the Depot made it through three rivets before pretty much stripping. So in the event that you every want to work with riveting on your boom or mast, get a better tool(s). I ordered what is supposed to be a professional tool from Jamestown Distributors. We will see how it holds up. West Marine sell SS rivets, but not tools (nice)! I plan on making new rigging next winter and the spreaders will be made over with sleeves between them then as well. Mast is up and my boat is now just waiting for a lift over to the pond! I will miss my little spot on the hard, it almost feels like home after all these months. Robbin M-23 and M-10