Colorized Photograph/Lithograph?

This piece is by noted photographer John W. Gregory. He is known for both photography and lithograph, usually scenes from Cape Cod, Ma. area.
I have seen several much smaller examples of this same image (sometimes a mirror image), but none this large (sight is approx. 13-1/2" x 10-1/2"), and always B&W or half-tone prints. Not only is this one colored, the colors on this piece are, if anything, brighter and deeper than in my photographs of it.
I can't figure out the technique on this one - some of the gray areas are shiny, like with a silver gelatin print, but all the colors are mat, almost like a lithograph.
The first image below shows the printed sheet taped to backing.
The second image shows it under the mat, and the angle highlights some of the shiny areas.
I've seen color tinted etchings and lithos - but never anything like this... It's almost as if a litho was tinted with the shiny gray to make it look like a photograph!
What do you say?

 

Could be hand tinted. That was pretty common, at least into the '60s.

This is a hand tinted B&W photo of Bluenose II from the studio of Maurice Crosby, Halifax, NS, probably from the late '60s

 

Agree with @moreotherstuff - hand coloured photo.

 

Cool - as I said, I have seen hand-tinted etchings & engravings, as well as hand-painted highlights on a lithograph, but I don't recall seeing hand-tinted photographs before.

 

Interesting, I thought they were quite common - or let's say USED to be common ...

 

http://www.metropostcard.com/print10-photochromo.html

 

Well, I certainly have not seen it all - even now!
Part of what I love best about this business - always learning!