Hey Chocolate Bunny, fortunately I can help you with this.
I've got three pictures on a book that show Huáscar
during the time period you're interested.
The first one is dated during the latter part of the War of the Pacific or during the immediate postwar. She's shown in grey livery, with her foremast reinstated, without an additional pole on it, her mainmast has a long pole added to the top and the spotting top is without canvas or solid covering, only railing.
The second picture is dated during the late 19th century, she sports a black hull colour with a white waterline and red hull (I'm guessing this, the pic is black and white
), the mainmast's spotting top has been removed and one has been added to the foremast, seemingly covered in canvas, lots of canvas is draped over structures on the weather deck.
The third picture is dated during the first third of the 20th century, she looks gray overall, in a bit of a sorry state, has most equipment missing and interestingly has what appears to be a muzzle loading bow chaser over the forecastle.
I'll try to get these scanned tomorrow so I can post them.
Also, according to this source, there were three restoration projects to turn her into a museum ship, the first one in 1924, then in 1951 and finally in 1971-72.
Finally, your description implies Captain Prat died commanding Huáscar
, I'd like to point out he died boarding her!
Anyways, hope it helps and keep on bucketing!
It would be great if you could provide those pictures. Very appreciated!