House from 1919 Lakewood Ohio. Updating drains for tub and bath sink. Diagnosis & repair

This job we didn’t know what we are for sure gonna get into. We had to open up the soffit in the kitchen and we realize a bunch of the drains were updated to PVC and firm code back into the original steel drain lines, but they were at completely messed up angles, and if we didn’t change them there’s been no way to keep the drain from backing up and having maintenance. 
We couldn’t find the drain line for the sink in the bathroom, and that was also clogging, but the toilets were flushing, so it didn’t seem to be a venting issue of the main stack to the roof
 So since we had room in the soffit, we just decided to go open up the wall in the kitchen that was already furred out and a false wall because it was covering a black wall. We also realize the original plumbing stack seem to be murdered into the black wall, so there was no accessing the old plumbing in Fernie going in some pieces in the PVC. We ended up having a run complete new line for the tub and the sink and combined them and tied into an updated 2 inch line from the kitchen of that side of that duplex unit in Lakewood, Ohio