Sante Fe drumhead, 1 to 1 version.
Oh yeah!!! That'd be very, very hard to top. I remember leavintracks' thread on the "find of a lifetime." The 1:1 drumhead tops that IMHO.
My find was attending a TCA show in the late '80's and making the acquaintance of one of the members with a table and a few items. He told me about some of the items he had purchased from Madison Hardware (2355, 2329, 746, 2332, etc.) mint w/o ob's that he had at home. He invited me down for a week-end visit (I was living in Chicago) which I did the next month.
Bought a ton of mint PW engines and had a great time with this TCA charter member. We stayed in touch; and, he had a son in the Chicago area, so we had my new friend and .his son and daughter-in-law over for dinner when he visited the following Christmas.