TMG is an EASA rating; SLMG is a National rating.
If you have a current TMG when you convert to an EASA licence, it should be entered on the front page of your EASA licence in Section XII, with a Certificate of Revalidation date duplicated from the licence which you are converting from.
If the TMG is expired, it will be on the reverse of the licence as a Rating previously held.
The CAA got my TMG wrong also.
ifitaint...