could an op07 be used in place of lm308?
Yes. IC1 and IC2 can be changed to anything that is substituted in other Rat builds. Note that depending on the IC that you use, you may have to change/omit the compensation capacitors (i.e., C2 and C6).
But LM308 has that special mojo! And eBay has real ones for $3 each. I know one of the original Expandora versions substituted a TL072 for the two 308s and nobody likes that version. Lost of complaints about it being very noisy compared to the others.
Just my opinion...