Military jacket, buttons, badge, help dating please

So as I showed this on the Finds Thread last night. This was indeed in with costumes
from our big city's opera company. Just given away, when they were thinning out theirwardrobe.

Am a bit bothered now that I know the history and will be treating it better, feel it
deserves more respect. It is wrinkled for now, and pretty unkempt.

Would like a more tighter timeline on the buttons/badge.

Would like to know a date range on the wool coat itself, it may have nothing to do with the buttons/badge. Pic of inside jacket sleeve area, which appears to be cotton,
which would match the hot locale, though.

Here are the pics I posted last night and some more. Used lighting and contrast on some.

It was fun discovering the buttons' background. Look closely at the button and see if
you can figure out what it says. It is like a treasure hunt. Love learning about history.

Haven't had as many finds as the rest of you and do not know if any part of this is
worth selling and where to do that. Wondering where it has been all these years and
how it got here--wish it could speak!

The adornments:
The jacket itself:

 

Some of the medal ribbons despite their dilapidated state resemble some British ribbons, such as the India General Service, and the 1945 Victory medal but they are, I am pretty sure, just a random assortment as if they were British, they'd be meaningless as mounted.

There is a strict order of precedence for wearing medals and their ribbons. Gallantry in seniority order first, leading with the VC, then Campaign medals in date order,then 'General' medals like the War Medal and the Victory medal, then special medals like Long Service and Good Conduct, then foreign medals.

Sketchy but you get the idea.

They may be US medal ribbons but the buttons seemed to be British.

I am pretty sure this is just theatrical costume assembled from whatever was handy.

 

Found out a few tidbits. The back of the buttons: the buttons were made in London by a company that went out of business around 1920. So that gave me an ending point for the buttons.

The front of the buttons say Rattray's Sikhs. Googled that and read a fascinating history of British forces in India.
http://www.britishempire.co.uk/forces/armyunits/indianinfantry/45thsikhs.htm

From what I read 45th battalion started in 1864 and ended in 1922 when it became part of the 3rd.

Regarding the coat itself, the sleeve area looks very much like this picture, which was from a Rattray's reunion in 1904.

Regarding the poorly executed ribbons on this jacket: some of the color patterns are similar to Lot 212 on this page:
http://www.dnw.co.uk/auction-archiv...hp?dept=Medals&keywords=RATTRAY&action=Search​