I found another way to correct this in PS. Could be a better way, because I can preview while dragging the edge. here it goes ...
1. Open the image
2. outline picture
3. drag vertical guide line out from the veritical side ruler to near the buildings
4. click Marquee tool, select all (ctrl + A)
5. menu -> edit transform -> perspective
6. drag the top right edge while matching the building to the vertical guideline
7. crop off excess
with this method, no need trial and error as compare to your early mentioned method :thumbsup: