first saw this guitar when it was in pieces. It has a lower bout measurement of 16 1/2″. (Further measurements are in this post). It is stamped on the top of the headstock with serial number 18,488 and Style number 30. It has the gold decal which was used from about 1910 to 1915.
Construction of this Jumbo; ladder braced Adirondak spruce soundboard, Brazilian rosewood back and sides, mahogany neck with rosewood fretboard, ebony bridge (handmade replacement). I was tempted to X-brace the guitar but as soon as I saw the craftsmanship of the ladder bracing I left it as is. I’m pleased I did, it has beautifully sculptured bracing.
(This video of a H.A. Weymann and Son c.1913 JUMBO Guitar is by guitarist and performer PRALAD, singing an age old kirtan meditation “Chaitanya, Chaitanya, Chaitanya Haribol – Nityananda, Nityananda, Nityananda Haribol!”)
There’s more about this guitar and Weymann Jumbos in general here.