We'd need to know :
b) bbl length (from cylinder to muzzle)
c) grips shape (round or square)
d) number of shots/cylinder bores
e) type of sights.
f) if there is a letter in front of or anywhere near the s/n on the bottom of the grip
That number, if it is the s/n, should come from the butt of the grip (or under the barrel or face of the cylinder).
A picture or two is worth A LOT of words in this case...