No. Half cock is a feature of single action revolvers, most Rossis are double action.
Your Rossi revolver fires the .38 special cartridge.
Rossi
50-250 usd
No published sn data
100-250 or so
50-200
No published sn data. You will have to call Rossi
Rossi M88: That may depend on when it was made. What is the serial number? That may help.
50-175 dollars
100-250
No published sn data that I am aware of.
100-300 USD or so