Door Casing Question

[kescue]

2018 Montana HC 381TH
Need to replace piece of Door Casing around door. Trekwood had it listed on their site for purchase (included pic from their web page). But when I received the shipping quote they said it was no longer available.
Trim - Door Casing - 3/8" x 1 1/4" x 96" - Carb 2 - MDF - Sprinter Walnut

Wanted to see if anyone know of another supplier or options.

Most likely will have to do the best I can to recreate the trim piece. Also looking for a router bit that would match that shape. Have not found it but looking!!

Thanks for any input or other options.

Keith