I guess it is a promotional version of the base 81520 set (for which there was an add-on set 81950). I take it there is just a Br89 and a single Mercedes labelled boxcar in your set.

Hello hope all is well

According to Z-Freunde-International, this is a special advertising set (werbemodelle)from 2002. While this is common today, it was unique at that time when each side of the refrigerator wagon had a different image. It is interesting the package has the mark (81520-000) you mentioned while Z-Freunde-International indicates the number as 81520-016. Looks complete.

Z scale train sets such as this are of special interest to collectors because they appeal to z collectors and Mercedes owners too.

There is no indication of the quantity of these sets, but similar sets have as few as 100. Since this set does not indicate the quantity, I would assume it was probably produced in a quantity of 3000 worldwide The set was likely available at the dealership at the time. Now you rarely see it in the secondary market and it should command a higher price but I cannot estimate a value.

A nice and fun find. That Br 89 should have a five pole motor for smooth operation I hope it works. Is it marked 89 2002? If it is, it likely belongs to this set. Sweet! I hope you got a bargain.

Take good care.

Zme