Lanny, I have specialized my collecting to percussion two-barreled over under guns and am particularly interested in Jacob Harder as he was a major maker of this type gun. Although I have no 3 barrel versions from him and none marked with the Waverly or Athens address, I do have 9 other percussion versions ( and one of his cartridge versions). My earliest version is a swivel breech without any town name stamping that I think was made just after he left his apprenticeship with Bartlett Brothers in Binghamton, NY. Thus I am extremely interested in your detailed history. As you undoubtedly know, his sons also made similar guns after moving out of Lock Haven, Pa. I am aware that a collector of his guns died in the last year or two and MAYBE another member can direct you to that collection.
Let me know by e-mail to WGLOWE@TDS.NET specifically what you need in the way of photos, info, etc & I'll try to send the info directly to you rather than bogging down the ALR link.
A question for you: It appears that Harder started serial numbering his guns when he began to stamp them "J Harder and Son". Is this also your finding, or?