Congrats, I have one, the first was in 1961 in East Africa.
I assume you are pulling the lever towards the steering wheel beyond the 1st-2nd gear positions and then up.
Check all the bushes including the ones under the steering wheel.
Have a look at mbzponton.org It's a US site wit plenty of information.

 

Thanks Mate, I will check it out.
That's why I bought it. I grew up in Africa and remember the Pontons everywhere. They were such a reliable car in it's day. Built like a tank and renown to be unbreakable. When I was in Jordan in the late 90s they were all the taxis, still going strong. Utterly loving it. Sure bliss.

 

I kept my EA Ponton for 7 years and was registered in 3 different countries.
Did nothing to suspension apart broken shocks, cylinder head off burnt valves.
Gearbox out to fix selectors, could only get gears 1, 3 and reverse. sent box to MB to fix
Taking the box out was easy, no mountings and I was much younger then!!!!

 

Thanks Nigel, You have been most helpful, and it is deeply appreciated.

 

If you do take the gear box out, remove it from bell housing, it's only 4 bolts and gear linkage and prop shafts bolts.
The transmission tunnel is large to accommodate auto clutch on 220s model so plenty of room to work.

 

I have the same problem of my rear gear. Cant find information on mbzponton.org about this subject. Is yours already fixed? What was the problem?

 

I was many decades ago. It was fixed by MB in Nairobi Kenya. It was some thing to with selector forks, indent ball bearing had fallen out
If you don't have a parts book use niemoller mercedes on the net to get exploded diagram of the parts.
Also the box use ATF automatic transmission oil. If it has gear oil EP90? it will be almost impassable to change gear when cold.

 

For got, the engine/gearbox mountings must be in A1 condition.
If the engine/gearbox have dropped 1/2 due to old sagging mountings the will effect the gear change and reverse very difficult
Also there will to much engine movement on bad roads and will pull it out of gear