Just so you know...Newmar offers about 5-6 dinette setups.
Lancer, if it is indeed missing, you can order the material from Newmar and have a cushioned made. I bought a yard of material and made a couple different upholstered items from it. I bought and fitted the foam, then had a professional sew it up.
Don & Mary
2019 Newmar Dutch Star 4018 (Freightliner)
2019 Ford Raptor