Parts of the letter observations (by classification):
Old Style... after looking through the hand out I noticed that Q's and R's have elongated tails, large eyes/counters in capital letters, not a lot of variation in stroke width, flat apexes usually bracketed, high cross bars, "cut off" finial, short barbs, closed loop
Transitional... thick and thin strokes, bracketed serifs, flat apexes (sometimes short), rounded finial, high cross bar, long barbs, thick bracketed spurs, open loops, long legs
Modern... hairline serifs leading to a lot of thick and thin variation, shorter x-height, unbracketed serifs, sharp apex, rounded finial, long barb, small spur, thin link, short tail and legs
Slab Serif... rectangular, uniform, unbracketed, flat apex, large counter/eye, low cross bar
Sans Serif... uniform, equal stroke width, low cross bar, high x-height, large eye/counter, "c" only has one barb, "g" open loop, long "k" stem, short "k" arm
Perpetua Characteristics
A- flat apex, 2 stroke weights, barbs on ends of stem, serif
a- tapered finial, short curved terminal, smaller eye, closed loop
d- two story, short tail, even stroke weight, counter
G- thin spur, flat bracketed serif, tapered finial, barb
g- long link, closed loop, flat ear, varying line weight
M- sharp vertex,bracketed serif, contrasting line width
Q- elongated curved tail, large counter, thinner stroke at top and bottom
x- varying stroke weight with each stem, bracketed serifs, even crotches
t- bracketed serif leads to the left top being filled in, short curved tail
4- sharp apex, contrasting stroke weight, extended ear, all straight or horizontal lines
?- tapered, one line, small gap between dot and terminal, open counter
The lowercase "t" appears to be closed in on the left side where the vertical and horizontal lines meet. The flat "g" ear is different from others, many tend to be curved.