A followup on this as I did order the "tall" front scope base from Numrich referenced in above post. It appears Numrich does indeed offer the correct front base for the No. 3 rifle; a big "but hold on" as I ordered two and got two different sizes... One was the correct No. 3, and the other is the 1V front base as you will see in the photos below. So it appears Numrich has a bin with mixed front sight bases and it may be a bit of a crap shoot to see which you would get when ordered. In photos below the 1V is on top with a "2" cast in underside. The No. 3 base has a "1" cast in underside. I confirmed measurements posted by Gramps51 and G2 in this and previous threads for the No. 3 base.