The 29 is from 1952 and was their first 29, the '53 model had the airfoiled exhaust. The 19 first appeared in 1950 and little is known about them other than there seems to have been 3 types. The first had a 7 fin head and round intake port with no anodising, the second had a 7 fin head with rectangular intake port and red head/prop driver while the third had an 8 fin head, rectangular intake and red head/prop driver. Also there's a difference between the red heads where some have straight fins while others, like yours, have a slight taper near the top most obvious on the outer head fins. It's not known if this is peculiar to the 7 or 8 fin heads.