H&R top break. Either .32 or .38 S&W (not .32 long or .38 special)
Do you maybe have a 38 special to try it with? A .38 special will fit in a 38 S&W hole, just not all the way in. If it is too small it is a .32 S&W.
Both of these cartridges are getting a bit difficult to find. A .32 acp will fit in the .32 S&W cylinder but in an H&R I would not fire it.
H&Rs do not have the value of Smith and Wessons. Depending on condition I would say $150 - $300 if you could find the right buyer. If they are in good shape the are quality pieces for fun shooting. However without reloading the cost of ammo will be high.