I shouldnt worry about it Old Duffer - the medal itself was one of the cheapest and nastiest medals ever to be presented to HM armed forces. The gold plating on the medal was of such a poor quality that warnings had to be given not to attempt to polish them. If you're really upset about it I can get you a copy for about £25 - and unusually the copies are better than the originals!
BTW
DD, did you know that before 1908 the predecessor to the Territorial Decoration (TD) was known as the Volunteer Decoration
Volunteer Decoration - Wikipedia, the free encyclopedia
- and it had post-nominal letters too?