Looks like a Terex AC350 to me, am I right?
For inspiration, look at the LTM1400 from Richard:
http://www.rmw-technoscalemodels.nl/...n/ltm1400.html
There are two of those BTW. I have often photographed this crane, and did some driving and hoisting as well.
He is also building a LR1750 crawler crane.
There are not a lot of cranes out there, always nice to see a crane build.
Kerst and Eef7260 here on the forum made some nice cranes as well.