Originally Posted By: mezzopiano
This is the only 49 keys weighted hammer action keys controller I'm aware of, but it required a lot of assembly and buyers weren't generally happy with:

I'd missed the Studiologic VMK-149 from 2005. It was advertised as "the world's first 49-note hammer-action controller".
Dimensions: 30.8" x 13.75" x 4.75" (782 x 350 x 120 mm)
Weight: 24.5 lb (11.1 kg)