Featured Japanese block print- some questions!

Yesterday I bought this Japanese block triptych print, I paid $60.
The whole piece measures 18x 31 inches.
Each panel is 9.5x 12 inches, perhaps an odd paper size? I understand that there were traditional sizes of paper for block printing.
I have deciphered that the artist is Toyohara Kunichika 1835-1900.
I'm sure it's a genuine block print. I have another print, and have previously done lots of research.
The frame job seems to have been done mid century, due to the style of frame, the silk covered mat, and the aged brown paper on the back.
The curious thing is it doesn't have any glass. It looks like there never was any glass. There is no gap between the frame and the mat.
I have looked all over the internet, and no one is showing a framed print without glass.
Any ideas as to why it was done this way?
I have not taken it apart to see if there are anymore clues inside.












Ad you can see here, there is no gap for a pane of glass

 

It's likely a later reproduction - contemporary with the frame. Does it look to be 3 separate sheets of paper?

 

Yes, it is three sheets of paper. Through a loupe, it looks like washi paper.
You can even see the grooves in the lady's hair from the pressure of the block.
It is definitely a genuine block print, but when was it printed? How can I tell?
Maybe a later print from an original set of blocks?
I'm intrigued

 

Be careful I wouldn't be surprised if the prints and mat are all glued down.

 

Yes, they appear to be. I might remove the bank paper, just go see if there are any notations inside.
I know that gluing Japanese block prints for framing is a big no-no! Who framed this thing? There is a faded stamp from a frame shop on the back, but I can't really make it out.

 

I have seen quite a few Japanese woodblock prints that have been treated this way (being glued or dry mounted). So unfortunate. The lack of glass is probably just another expedient decision.