Rock Island Auction has a Rigby howdah pistol as its Item 3433. See https://www.rockislandauction.com/detail...-577-cartridge.

RIA believes that this pistol will sell for between $7,500 & $11,000.

This pistol is describes as follows:

Lot 3433: John Rigby & Co. Howdah Double Barrel Pistol in .577 Cartridge

Auction Date: August 27, 2023

Originally developed by dangerous game hunters in India, the Howdah pistol is named for the elaborate elephant-mounted saddle/carriage that tiger hunters would shoot from. In general, Howdah pistols are large caliber handguns and many have two or more barrels. The gunsmiths of London, such as John Rigby & Co, responded to this new demand with purpose and built large-bore pistols with enough power to stop tigers dead in its tracks. This example has dovetailed blade and three leaf rear sights on a solid rib signed "JOHN RIGBY & Co. DUBLIN & LONDON." A fine scroll and border engraved motif is featured on the frame, hammers, upper tang, and barrel wedge escutcheons. An engraved tiger is featured on each lock plate. The barrel release lever is located ahead of the trigger guard. The barrels are brown Damascus, the hammers and trigger guard are blue, and the remaining surfaces are casehardened. The stock and forearm are checkered, and the butt cap is horn.

Fine as professionally refinished overall. The barrels retain 99% plus of the brown Damascus. The hammers and trigger guard retain 98% of the blue finish with an area of minor spotting. The remaining surfaces retain 95% of the case colors. The wood is also fine with sharp recut checkering overall. Mechanically excellent.

Discussion thread:
http://forums.nitroexpress.com/showflat.php?Cat=0&Number=378165&an=&page=0&vc=1