[sergejnowo]

Seriy, in general, after the introduction of a single customs union, the old agreement are only valid in the light of new laws.
At its core, the process of painting vvoza clear and stable, but .. nuances of the design is currently heavily dependent on the customs authorities in the field and the details are extremely volatile. Such processes need to be given into the hands of professionals.
In short:
If a public exhibition (if private, then you have to pay all fees and do not grieve), it is necessary to issue a temporary import into the picture, - vorübergehende einfuhr. With this import customs (the state) takes a certain amount of bail (in the worst case: import duty + VAT). In your case, this amount is incident is just 7%, a VAT, import duties, in this case does not. Nuances in the dark, with a local general can not take a pledge, or only half, for example. Registration can be documented or verbal - such as calling on the phone.
Your "state institution of the Russian Federation in Germany," if it deals with these things on a regular basis, should know about it. If not, then let him seek a specialized firm near the German names of such firms "Zolldeklarant", they all tell and show.