[R-390] No "Depot Dawg"

[James Miller]

I don't believe there is any downside to having a so called depot dog. 
The 390a was specified by the government and designed to be modular for
maintainability.  The swapping of modules was expected, and the
specification requirements demanded that modularity and
maintainability.  Therefore, an R-390 that has a mix of modules while
still meeting government specs. is actually living proof of the
excellent design for modularity.  An R-390a is an R-390a regardless of
who made the modules.  

After all, just because they swap assemblies and engines between Space
Shuttles certainly doesn't make it a depot dog!  It proves its worth.