So thats all the 156s done. 1x158 and 1x170 done. Slow progress.
Well, not the First liveried 156s. They're still as they are (and, considering they've only been in those colours for a few years, I doubt they'll be top priority).
The reason the progress is slow is because, other than 170434 (the launch unit), they're just being done as and when needed. So, the SPT 156s were the oldest units with the carmine and cream livery, and the 320s just after them.
320s will be reliveried soon (and, to be fair, they're about due new colours and an internal refresh). 318s, probably later because they've had a refresh fairly recently. 314s aren't being done for obvious reasons (only a few more years left, all going well). And 334s are going to be started for Airdrie-Bathgate.
I think 170s and 158s will actually be the last ones to be completely done, simply because they've only recently been painted into First colours.