The conversion of the bogies to newer design requires a bit of manual skill. However, you can save a lot of money, because you do not need to replace the entire bogie, but only to purchase a set of couplings and the adapter described here.
Until the 70s of the last century, LGB® used the old coupling system, with the coupling eyelet (bottle opener) molded onto the bogie and the coupling hook only movable vertically.
Problem of this system was or is that a safe driving with double coupling hooks (front and rear of the car) is not possible here. A mixed operation with the newer couplings is problematic and not reliable.
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