Is there any timescale for conversion of the six remaining 77Ws to CS?

I read somewhere that there was parts shortage which had slowed the project down. Has this been resolved? It doesn’t look like any 77W is currently Cardiff bound for the works……

Also, any news on which fleet will be converted next? I had heard it was likely to be the 789s rather than the 788s as the latter may end up going to Gatwick as more 7810s are delivered to LHR.