Hi,
I translated the smith on this paper as Mishina Kanemitsu. I never heard of him, but apparently it's another name for the sandai Kanemichi.
Kanemichi, 3rd generation, 1711, Settsu, Tango (no) Kami Kanemichi 丹後守兼道. He's the adopted son of the nidai. Fujishiro listed him as Mishina Tajima (no) Kami Minamoto Kanemitsu and died in 1732
KANEMITSU MISHINA [HEI 1704 SETTSU] SHINT CHJSAKU
He is called Mishina Monday, is the adopted son of nidai Kanemichi, and he died in Kyh Jshichinen (1732).
Signature: MISHINA TAJIMA NO KAMI MINAMOTO KANEMITSU
The date to me seems 享保 Kyôhô 12 so 1728 (which would fit the description). Can anyone give me more info about what the origami says about the mei ? It's being sold as a Gassan blade strangely enough, although if you look at the hada, you'll see why :-)