Thats excellent! those old pics are what Ive been looking at , Thing is theres also camera lens distortion to consider when measuring angles .
I blew the page up to 200% then measured the visible , inside wheel rims , Front vertical = 75mm , horizontal 77mm
Rear vertical = 74mm , horizontal 76mm
so the wheels in the pic arent round , so frame angles could be and likely arent actual
I measure
top tube to down tube 45*
top tube to seat post 68*
seat post to down tube 67*
total 180*
seat post to top stay 55*
seat post to bottom stay 60*
top - bottom stay 65*
total 180*
the angle of the head to top tube 20*
but because of lens distortion all those measurements can mean NOTHING!!
Now.... your frame , because its got angles 67.5* and 0.0* on the top tube as a bench mark its easier
top tube to down tube 47*
top tube to seat post 66*
seat post to down tube 67*
seat post to top stay 49*
seat post bottom stay 59*
top - bottom stay 72*
the head is 23.5* to the top tube to match the 67.5*
tricky bit = Ive got flat screen to measure off but when I blow the pic up to 200% to measure the wheels
front wheel vertical 99mm , horizontal 100mm
rear wheel vertical 99mm , horizontal 100mm
so even though theres a person attached to this diagram who can double check my measurements and tell me Im wrong , I have to be skeptical of my OWN measurements because I can see distorion in the screen or in the case of 100 year old photos , camera lens distortion . Even scanned pics show distortion so they are also not reliable
Ive been looking a old Hendee and Indian bicycle frame geometry and it caves in when I can see the distorion that most people wouldnt even notice.
heres 2 pics
one is 20 degrees from head bearing flat to the top tube of 1922 - 31 indian chief motor cycle
one is 25 degrees from head bearing flat to the top tube of 1920 - 31 indian scout motor cycle
how this is relavant is from Hendee bicycles evolving into mc , there must have been angles and geometry that Hendee saw as suitable being a racer from diamond frame then to hoop then cradle frame mc in the art deco era