Hello forum members. I've just joined in the hope someone can help with some information on set number R2788. I am trying to find out when it was released as my cousin wants to sell her set. I have found another set with loco 6224 in it but this seems to be R2371M with a run of 1500 on the certificate; my cousin's has the same number loco but her certificate shows a run of 2000. Any ideas? TIA