Ok one more ?? about markings on my 1918 Erfurt

thanks a lot for the information about the 8's. there are three 8's underneath my barrel. a large 8, a comma and a small 8. the number 121 also appears there and in between the 121 and the 8's there is a little swoosh or curlique. i wonder what that is? help please.thanks in advance. lawrence fredrick klang.