They're on two walls, in between Kooyong and Glenferrie Roads, if anyone else wants to check them out. Below are Linda's photos - I plan to get there myself in the next few days:
I've also been alerted (thanks Mark!) to another uncovering in 2010 in Rosebud, when the skate centre was demolished. Apparently the signs (a Swallows biscuits sign and a Medallion foods one) are still there next to a new Shell service station,and are a source of admiration for the locals. I can't show the photo here - I don't have rights - but the link is here: http://www.flickr.com/photos/23651645@N03/5134631793/. I plan to get there soon too. Given that Swallow and Ariell, as well as Groves McWhitty (maker of Medallion foods) were Lewis & Skinner clients in the early 1950s when these signs were probably painted, it's highly likely this was a L&S sign.