Awesome man, glad they finally arrived.
I was going with info based on some similar pipes for sale by "Valitchka" on Ebay, but cant seem to find the auctions. He seems to have a thing for old Kaywoodies and a lot of knowledge too.
The thing that really narrows it down is the "Synchrostem Pat. App. For" stamp.
The synchrostem patent was granted in 1931, so its earlier than that.
The Algerian Briar stamp was used only in the 1920's (according to Valitchka) so that stamp means its 20's.
The synchrostem patent was applied for in 1928, so put the two together for a likely 1928-1929, but definitely 1928-1931.
The second one doesnt have enough stamps to narrow it down as precisely, but the KBB inside a clover leaf stamp was dropped when Kaywoodie left their factory in Union City NJ in 1933, so its earlier than that.
Enjoy them. I didnt smoke either one, but they seem like damn fine pipes to me !