Through the Subway past Lo car ar (To the car park)

I headed out through the Bus Station Subway, this time with the intention of continuing my derive. I was immediately confronted with an oncoming pedestrian, who I walked into on the right hand side of the subway, underneath one of the intermittent 'Keep Left' signs installed....
After my minor lawlessness  I spotted some other signs in the subway which caught my interest. These signs had absent letters and letter parts, which led me to consider lettering repairs. A walk around further parts of the station later led me to other signs with missing lettering parts. Would I be allowed to restore these signs? Perhaps ironically not, due to the building's listed status? Temporarily though maybe? This was something to consider further.