If you find some can you send me a photo of the seats? The 1927 yankee I am restoring has none and I would like to get close to the original look and proportions. I can’t part with my original thwarts but can give you measurements and photos if you need
The image at https://forums.wcha.org/attachments/322/ shows the bow seat from a 1936 Yankee in AA grade and the one below shows a stern seat from the same year in CS grade. Old Town seats on most models in the 1920s and 1930s tended to be very similar so other examples from that era and the classified listing archive at https://wcha.org/classified-archive/Old-Town.html may help too. Good luck,
Neither - they are joined with a pair of dowels at each junction. The attached photo (added after Benson's comment below) of bow and stern seat frames, disassembled, shows the dowels but you cannot see their insertions. They are simply paired up, evenly spaced at each junction. Where you see only one in one of the pieces in this photo, that's because the other half of the pair is in the mating piece of the seat frame. This is from a 1930 HW, but your 1927 Yankee shield be the same if its seat frames are original. I've restored several of Yankees from that timeframe and they are just like other Old Towns and Carleton's from that era. I don't have access to such a seat frame right now, but I believe the dowels are about 1/4" diameter by about 1.5" long.