This Horton "Poly Grip" is a very nice gun and the intercepting sears are not complicated parts. Thin flat spring provides the tension, again not complicated to make. For a gun of this quality I would have the missing sear and spring duplicated to complete what the gun maker intended. Each gun would have to be evaluated as to the expense of fitting a missing intercepting sear and spring, but for two easily duplicated parts I'd do it. Lesser quality gun probably not. Especially of both were missing and no pattern part was present.