The earliest Winchester moulds were made of brass, with no company markings. According to Chamberlain, there should be a very small number (perhaps a serial number) stamped on it somewhere.
That looks like a pristine specimen, wow!
The one on the right certainly looks like another Winchester. The one on the left, I dunno. The handle shapes, hinge and sprue cutter look maybe like the designs some of the smaller gunsmithing shops out West made for their customers, but I don't know whether they made them of brass.
You might ask the guys at the Antique Reloading Tool Collectors' web site about the dual cavity mould.
|BP||Bronze Point||IMR||Improved Military Rifle||PTD||Pointed|
|BR||Bench Rest||M||Magnum||RN||Round Nose|
|BT||Boat Tail||PL||Power-Lokt||SP||Soft Point|
|C||Compressed Charge||PR||Primer||SPCL||Soft Point "Core-Lokt"|
|HP||Hollow Point||PSPCL||Pointed Soft Point "Core Lokt"||C.O.L.||Cartridge Overall Length|
|PSP||Pointed Soft Point||Spz||Spitzer Point||SBT||Spitzer Boat Tail|
|LRN||Lead Round Nose||LWC||Lead Wad Cutter||LSWC||Lead Semi Wad Cutter|