What is information about the model 36 Winchester rimfire shotgun patent date Aug 1899?

Made from 1920 to 1927. Barrell length under 18" so was a short barrelled shotgun, but removed from NFA and re-classified as a Curio and Relic. Only 20,700 ever made. Hard to find ammo for, approx $3/shell. Asking price $400 to $1800 depending on quality. Update: Fiocchi has begun making ammo that fits this model. It's listed as a "specialty" product with the specific designations, 9FLS8 and 9FLS9. You can buy a box of 50 for around $24.00. My local gun shop ordered some for me.