I'm wondering if I've missed an announcement about these trains...
It seemed from posts much earlier in this thread that the current SWR management had no intention of using the 4-car 458/4s in service. The prototypes of the conversion would be completed and tested in accordance with the initial contract, and would then be stored pending a decision at some future time as to whether the rest of the 458/5 fleet would be converted and redeployed as previously planned.
But now it seems that four /4 units have already been completed with at least two more in preparation, which seems rather more than just completing the initial prototypes. Have SWR decided to continue with the conversions, and so they will eventually turn up to replace the 450s on the Direct? Surely after the wastefulness of the 442 and 769/9 fleets being rebuilt and then never used, we're not going to see another fleet following their example? Apart from anything else, there can be little space available for storing a load of 458/4s in addition to all the 701s cluttering up the available storage locations.
So is there any reliable information regarding how many units will be converted in the current tranche of work?