"dougga" wrote in message
The pipes for the toilet are at this point ABS.

I'm thinking I have to rebuild some sort of flat base for it... but what
to
do with the pipes that are aligned for the current base?

Assistance please?

Have you removed the toilet yet to see what the condition is? The ABS is
relatively new and may be in good enough shape that you don't have to change
it. Can you replace some of the floorboards and shim then to proper height?
Wax seal would have to be new of course.