Translation+Stamp Recognizing Help, Rather Weird Tanto

[Pika007]

A friend of mine just popped out of nowhere with a blade, and asked me to help him recognize it-

I can't read this mei, nor do i have an idea what this stamp is, never seen anything like it before even in the books.

 

 

 

I'm guessing shinshinto at the earliest, to meiji/modern, by the shape of the stamp (very precise and symetric, looks machine made) and how the blade itself looks. The nakago looks like it's a lot older though, so that's really throwing me off

 

Any help would be much appreciated. Thanks

[mywei]

(Suishinshi) Masahide + kokuin

 

Not sure about authenticity, I'm sure more knowledgeable (shinshinto) collectors can help.

[Pika007]

I'll ask in the nihonto forum then

Thanks for helping me recognzie the signature. the "masa" is rather squashed here, didn't manage to read it