Nihonto Club

Dear All, I am a new member to Nihonto Club with a life long interest in Japanese antiquities. I recently acquired a sword which I have not been able to categorise and I would appreciate any help from other members who may have an idea what the sword was for:

Showa period Tachi style
Ashi are stylised Frogs gripping a leather bound metal saya (gilt copper, poor quality casting)
Fuchi, Kabutogane and Kuchigane also frogs
Tsuba, again poor casting with flowers and pots gilt on copper
Menuki are thinly cast gilt fish
Thin ray skin is applied to the hilt which is poorly bound.
The Habaki is the only marked copper fitting, 717777

The blade is interesting. Unmistakable Gassan style with clear Ayasugi grain.
Poorly finished but heavy and clean enough to take another polish.
The tang is 'roughly' shaped and shows deep forge marks....burs are still in evidence including around the mekugi-ana
The mei is clearly chiselled Yama Guchi Sen....(sen not san or maybe Kawa)

I am only aware of one Gassan swordsmith using the name Yamaguchi (SAD 856) but I don't understand why such a maker would use such poor fittings and seemingly leave the tang unfinished unless for some cheap touristy use? I don't have any reference to the signature style for this maker or, the other possible smiths being Kajimura Akikuni, Fujimura Kunitoshi or Okafuji Masaru.

I've not seen anything like this in my reference library. I attempted to load some pictures but couldn't get anything decent under 2 meg (sorry)...Hope someone out there has an idea on the intended market which desnt appear to be military in nature despite the period of production.

Kind Regards,

Haydn.