Its taken awhile, but finally my Vendettas have some rules bringing them up to par with Death from the Skies rules.
I will admit though that this concerns me a little that Forgeworld had to do these. I just lament my Colossus and other variantsvehicles leaving the GW codex.
https://www.forgeworld.co.uk/resources/fw_site/fw_pdfs/Warhammer_40000/Vendetta_Gunship_update.pdf