We would have been screwed without it.
We got through Bosnia and Serbia ok. Turkey I think we had to show it, Georgia was fine. Russia was the big one as we had to do 2 customs declarations.
Kazakhstan, Uzbekistan, Tajikistan, Afghanistan and Kyrgyzstan didn't care much and on our 2nd entry to Kazakhstan I insisted I needed the customs declaration from them for the trailer or I would be in trouble leaving Russia (They are part of a joint customs union). He wasn't having any of it. told me it would be fine and to leave
####.
Anyway, When we entered mongolia it was fine, the russians said nothing, phew!
Re-entered Russia for the last time yesterday and they were so hot on it they started to question the number plates (being the same as its the only place in the world who do it) and look more closely at my paperwork. A few phonecalls later and we were on our way.
It would have been a different story for sure had we not done something about it before leaving, so thanks again Bevhelee.
G