Dash surround is as good a name as any! I've also heard it referred to as a dash shroud, FWIW.
Rare Spares and Harrisons Early Holden Spares both stock this item. I've heard less than exemplary comments about the RS one from several sources, although HEHS may well get theirs from the same supplier
The problem with the two RS ones (insufficient plastic in the mould to form the screw holes) was not in the example I know of bought from HEHS. If you buy it from RS, make sure you check it thoroughly before leaving the store.
Around $40 I think. $40 saved by owning an FE
Rare Spares websiteHarrisons Early Holden Spares websiteHope that helps,
RET