I have MTH RailKing Sante Fe Imperial Northern Steam Engine, Item # 30-1562-1, the engine comes equipped with a 30mm draw bar, when I unpacked the box there was a bag with a 50mm draw bar and it states to be used with 0-31 S-curves, I have a couple of 31 curves but no S-curves, so, should I replace the 30mm with the 50mm.
Thanks
Tom