I'm doing a restoration on a 16' Charles River Old Town with a serial number 33608, built in 1915... Was surprised to find counter sunk steels bolts were used to attach both the seats and thwarts. The canoe has open gunwales. I think the seats are replacements of the originals but the thwarts appear to be original... I am also doing a restoration on another 16' Old Town.. 80382 which was built in 1924. The diamond headed brass bolts are evident in the 1924 model. Is it possible the counter sunk steel bolts are original? The flat head steel bolts themselves are unique as the heads are round and flat with no screwdriver slots...have never seen anything like them before. My limited experience tells me that the original Diamond head brass bolts were replaced at some point in favor of having smooth gunwales from stem to stern. If that is true I will replace them with home manufactured replicas of the original diamond shaped brass bolts.. Is there any history out there to show that the steel bolts could be original? Harold