M113A1 MRV

Joel
Has anyone built this model and how did you find it? I'm having trouble with fittings aligning however that may just be my lack of experience.
The one issue I have is the model has a few iterations and instead of taking the old parts/sprues out they have just added the sprues for the newer versions, which means there are many parts to sort through. I guess the good thing about this is that I could find the instructions for the older versions here and probably build any of them with the amount of parts I have.