It could be a challenge to identify which märklin article (catalogue no) a new object refers to. We in MRW have so far collected more than 11.000 articles in our database - Many of them before 2000 when märklin started to systemize their own product database.
The MRW märklin H0 database is public. You are of welcome to propose corrections and add new märklin articles if you miss objects you have in your own collection.