I know we have postings on repairing dash pads but I came across this company just trying to see what else there is out on the innerwebs on repairing a cracked dash. It was a interesting video with them repairing a dash & looks like an option.
Padded Dashboard Filler | Padded Dash Filler
Padded Dashboard Crack Filler. Part No. 2050-9 from Polyvance. Padded Dash Filler
www.polyvance.com