Hey guys, thanks the comments. I suspect a lot of people get caught up in the romance of building a car capable of crossing various galaxies when in reality the majority of countries have reasonable tarmac'd roads these days. The roads in the Stans are generally acceptable for a well built car and distances between towns reasonable (3-400kms usually). Of course there are known mountain 'adventure roads' that can only be driven in summer but in general unless you are actively looking for off road driving roads are ok - the USSR has a nation of Lada drivers remember. Likewise if you cross from Kazakstan into Xinjiang, NW China, the roads are fine so you can save money not having to go overboard in the rambo department.
Brutus, the W123 is the indestructible MB... I'm sorely tempted to try it. Being a low budget car if it all goes t's up you can afford to walk away!
This couple are going round central asia in a Defender 130, must have cost a fortune to put together.
https://www.youtube.com/watch?v=bRvoDAcoDLg