Progress, progress. On both fronts. Firstly, exhausted last SIMS tech so new one today has found that SIMS Server local firewall causing the logon problem since Autumn update forced by Solus2. Who Knew! Not made any changes to that in the last few days, weeks etc.
Secondly, looks like he has got Solus3 rolling out the 3.4.103 Solus update on the few machines turned on. Hope it works as I now need it to roll out Autumn update before monday. Don't see how it can with network throttling.
We'll see. Thanks for your input guys.