It would be interesting to see "before" measurements.
One trick on viewing SMD parts is to take a good picture with a smartphone or digital camera and then zoom in to view the fine print. SMD parts typically don't have real names on them like "2n3904" but have codes. There are code lists on the web to help translate them though.
To check power at lower power levels (like the ubitx) you can use a diode RF probe. Easy to make from scratch or as a kit. Some QRP dummy loads have them built in (e.g. Elecraft, QRPGuys, QRP-Labs all have them).
If I remember correctly, I think changing Q90 and its biasing makes the biggest different in evening the output.