That's an interesting question. I have no idea.
One hint may be that there is not a single plan for an oar in the
Haffenreffer-Herreshoff collection at M.I.T. There are four plans for
oar locks and we know that HMCo made those, though.
When HMCo was auctioned off in 1924 the inventory listed "374 ft. ash
oars, (new), 24 pieces, 6 to 10 ft.", but we do not know if these were
HMCo made or not.
