I had kept the number 4 spare as I originally intended building a model of the first Tralee and Dingle loco to bear that number; plans for that project have now been abandoned, and as I don't like gaps in numbering systems, I have given the number to the ex Ballymena and Larne loco.
This involved removal of the original No. 9 oval plates - they fell off anyway! I also decided to relocate the numbers to the middle of the side tanks, above the nameplates; I ordered some matching No. 4 plates from MDC. The paintwork under the original plates was intact, and I was able to remove the remaining silicone adhesive by gently scraping it away with a fingernail and then giving the area a wash with a piece of kitchen towel soaked in white spirit.
Like the nameplates, the new numbers were fixed in place with cyano adhesive, the paint under the plates was gently scraped away with the tip of a small screwdriver; this was in order to ensure the plates were fixed to the loco and not just a layer of paint! A piece of Plastikard strip was used as a spacer to ensure the plates were square with the nameplates.
There is still a gap in the numbering system - number 7 - but I have plans to remedy that!