For those that don't always read the comments, here is a round-up of query posts that have been resolved or have moved on a bit.
Not The Nine O'clock News - Baby On The Bus Sketch (13 October 2013)
The possible name I had of Robina Gange was corrected to Robina Gauge. Along with two uncredited appearances she made in consecutive episodes of Are You Being Served.
Are You Being Served has recently been showing every weekday afternoon on BBC2. When they came around, I recorded the two episodes in question, "Mrs Slocombe, Senior Person" and "The Hero", to see if I could spot the same woman as seen in the sketch. However I could not, and nor was there any obvious commonality of the same extra seen in both episodes. So either she appeared without her face being clearly seen or Robina Gauge is someone else and not the woman in the Not The Nine O'clock News: Baby On The Bus sketch.
It would seem now that the only way to progress this query any further would be to find out if there were any other uncredited roles listed for that particular episode of Not The Nine O'Clock News.
Unidentified Actress in 1983 Drama STUDIO (20 October 2013)
SOLVED: The name of the actress playing Liz has been identified as Paula Kitt.
Actresses to be Identified #1 (3 November 2013)
SOLVED: The actress in the Living TV trailer has been identified as Helen Goldwyn, via her own words in an online interview she did.
Unknown Drama #6 (15 December 2013)
RESOLVED: Information received shows that Julie La Rousse did indeed appear in Scene: Ties.