Found in my late Aunt's possessions. Photograph of unidentified uniform:
It looks, with the tapering frogging connecting at the single, center row of buttons, you may have a Royal Horse Artillery uniform. Some better images can be seem on a forum here. Another forum has this image. (note similar positioning of the aiguillette). (Note the feature I identified as an aiguillette may also be described in this case as a busby line, cap line or body line. See (commercial site) here.
Another more detailed image of a similar uniform jacket can be found at Museums Victoria Collections labeled as 'Jacket - Victorian Horse Artillery, Full Dress, circa 1890' :
Concerning the medals, they would appear to be Campaign Medals. However without color or a more precise time frame they are difficult to match.