It is not difficult to convert a generic US Civil War canteen to a British 1895 General Service water bottle.
The example below is a US Civil War era reproduction canteen from S & S Firearms, a re-enactment sutler from New York.
The US canteen is slightly bigger in profile and the spout is too short, however these are minor differences and I chose not to correct them.
To start the conversion, the wrong colour fabric cover is taken off, as is the cotton sling.
The British canteen was made from enameled wrought iron. To duplicate or approximate this look, I ordered a stainless steel canteen. Steel wool is used to rough up the surface to prepare it for the enamel.
In the British Army, the mounted service used a leather sling. The width of the leather was originally 5/8", but the US repro canteen came with 3/4" metal loops so I used 3/4" belt leather sourced from Tandy Leather. The leather is 6/7 oz thickness. The length of the sling as stated in Pierre Turners book, "Soldiers' Accoutrements of the British Army 1750 - 1900" is 5'6" made of two pieces that are spliced. The sling has two keepers. The one right behind the buckle is fixed and the other is loose.
The leather is dyed using the light brown Fiebing Professional Dye sourced from Tandy Leather. I mixed one part dye to one part methyl hydrate to lighten the colour and extend the amount of dye. The buckle I used is a 3/4" brass roll buckle also from Tandy Leather.
The original metal eye bolt that goes through the cork stopper is too thin and the eye is too big for the British Army model. So I purchased a stainless steel 3/16" width eye bolt with a smaller eye and a nut to go with it from Canadian Tire. I used a regular drill bit to open up the cork stopper enough to fit the new eye bolt. The chain that came with the original is also too thin and the wrong metal finish (steel rather than the nickeled brass that British canteens used). I could not find nickeled brass, so I just used a brass chain since there are some historic examples of private purchase canteens that have no nickle finish.
To enamel the canteen, I used the Rust-Oleum brand enamel paint. The shade was slightly lighter than I would have liked, but my research showed that there were many different colours used as well as shades of blue.
This brand of enamel paint was not easy to work with. If the air was humid, the paint tended to crack and if it was applied in too thick of a layer it ran and dried unevenly. This required sunny, dry days and application by very thin layers. I lost count as to how many layers I applied. With patience, an even finish can be achieved. The lip at the top I left unenameled so I could use it to drink from.
The new fabric cover is melton wool from Fabricland. I lucked out on the colour which is generally hard to come by. Again, historic examples show that there was a variety of colours and tones used, anywhere from dark grey to all kinds of beige and khaki. I specifically wanted a true khaki. I took apart the original cover that came with the canteen and used it as a pattern to create the new one.
The final product is not an exact copy, but close enough that I am comfortable using it with my Boer War kit.
After having used the canteen for one event, everything functions quite well, however the Rust-Oleum enamel has chipped in a couple of places. This could be due to the fact that it was applied in winter when the air was humid and cold.
All in all, this is a relatively quick and easy way to reproduce a pattern 1895 British General Service Water Bottle.