Dating british glass backstamps
This is clearly 19th century because it does not have the England or the later made in England marks.
The two choices you have given 1895 or 1868 sound about right. Based on the size, its intended use I would have guessed 1870's so 1868 would be a good choice.
The photograph that I have chosen is one from my collection that is a print rather than a postcard, although it does appear to have been published as a postcard, as I will demonstrate.
The photograph shows a procession of six decorated electric trams – known in North America as streetcars or trolleys – as well as a horse and cart being driven away from the photographer down the opposite side of the street and several individuals and groups of people, including the tram drivers – referred to as motormen – and conductors.
This is card 113 in a series by Lever Bros., Fine Art Dealers who were a local firm in Derby. It depicts the same Derby Corporation electric tram number 3, festooned with decorations and a sign denoting it as a “special car,” with another tram (perhaps number 2) in partial view behind it, and the motorman and conductor in clear view.
[The operation] started life as a horse tramway opened by the Derby Tramways Co. In 1899 the company was taken over by Derby Corporation who set about improving and then electrifying the tramway with the first electric routes opening on 27th July 1904 from The Spot to the Harrington Arms in Alvaston, a branch to the Midland Railway Station and from The Spot to Abingdon Street where the depot was located. They were fitted with 5ft 6in wheelbase Brush AA type four-wheel trucks with two BTH GE52 25hp motors and General Electric K10 controllers. In the 1930s, in common with many other British tramways, it was decided to replace the trams by trolleybuses, with the last tram running on 2nd July 1934, the trolleybuses themselves being withdrawn on 9th September 1967. Picture the Past‘s caption states: Car 3 at the front of a 6 car cavalcade on the first day of Derby Corporation Electric Tramways operation, wednesday, 27 July 1904.
Quality does vary in what's available but prices are very low with lots of choice for collectors. The reason being that it only has a single letter mark rather that a 3 character date mark.In Derby, after first being proposed in 1889, the Electric Light Station was built in 1893 on Sowter Road – next to the Old Silk Mill and very close to the town centre – and opened on 10 October 1893 [Source: The Derby Mercury, ].Initially used only for the lighting of streets, shops and private houses, it was subsequently expanded several times to cater for the high demand created by developments such as the electric tram system.The 'X' under the Wedgwood name looks more like potters marks rather than a date mark - the single impressed character mark could be a J or a C or even a U.Your right the single date late indicates from what I have read a pre 1860 date. There appear to be lots of variations of the Wedgewood stamp, periods with no production of Jasperware and no indication of what year that letter relates to if it is a date code at all. There is lots on the web to get through, although lots appear to be copies of other data so do check the facts are that and not a mistake copied across multiple sites (it happens).