The button offers more immediate clues.
The Prince of Wales Own (West Yorkshire) Regt weren't so called until the reforms of 1881.
Before that they were the 14th Buckinghamshire Regt, so a complete change of name.
So the button can't be any earlier than 1881, which at least fits in with your 1885 theory.
The "lion" in the centre is in fact an Indian tiger
They were awarded the Royal Tiger badge superscribed India in 1838 for services in 1807-33 on the subcontinent.
They also had the battle honour for Waterloo.