How would the ATPL GS be valid without a PPL? I was under the impression you needed a PPL and a Class 1 medical in order to get on the ATPL GS?
I'm sure there is nothing stopping a OAA student in dropping out halfway through an integrated course at the point where he/she has 100hrs under their belt and then sitting a PPL test at another modular flying school so long as they have:
25 hours of dual instruction
10 hours or more of solo flying
5 hours or more of solo 'cross country' time
Maybe they can walk away with the ATPL GS credit having never sat in a plane before but I've never heard of it?
For the record MikeeGR is modular so he doesn't have that problem (We worked it out via PM). 
All the best with finding the money though, CDL may work but we'll have to see.