Thinking this may be a first (four digit serial number less than 4000) or second model. Looks like it's lived the life of a highly respected safe queen, about 90-95%
.38 double action top break
the left side has what appears to be a removable, round(ish) panel between the cylinder and grip with one screw. black grips with S&W logo.
top of barrel is stamped as follows: SMITH & WESSON SPRINGFIELD MASS. U.S.A. PAT'D JAN 17&24 65 JULY 11 65 AUG 24 69 JULY 25 71 DEC 3 79 MAY 11&25 1880
(the dates are as accurate as I could read without a magnifying glass)
a) caliber - .38
b) bbl length (from cylinder to muzzle) - 3-1/4"
c) grips shape (round or square) - round
d) number of shots/cylinder bores - five (5)
e) type of sights. - fixed, front 1/2 round, rear, very small notch
f) serial number, and if there is a letter in front of or anywhere near the s/n on the bottom of the grip - four digit 30xx
g) Model number if it is under the crane.
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).
Thanks for the help