Murphydog gives good advice. If it is in excellent condition with original serial number matching stocks/grips (serial number stamped on inside of one of the stocks) then $900-$1000 is probably a reasonable estimate. If it's an earlier 35-1, i.e. prior to 1968 with diamond stocks then add another $50-$100, and if it's even earlier, i.e. prior to 1966 and has flat latch thumb piece add another $50-100, and if it has the original box in good condition then add another $50-$100. At a gun show this weekend a seller had an early 35-1 with flat latch and diamond grips in box in excellent condition and was asking $1350. It was still for sale on day 2 of the 2 day show but there appeared to be significant interest in it from a number of potential buyers including me. Pictures would help in better answering your question.
Yes, I am aware you stated "Bought in 1967 new" but it could still have a flat latch.