It's a really dated old look. I'd look for a fresher style.

Any ideas?

there is existing red brick along the bottom half of the wall which the client would like to keep. Going for a rustic/glam kind of style, polished concrete floors, black steel accents, calcutta table tops etc...

IMO we need more info and for sure an explanation of the reason for shiplap which IMO is already a dated look. What is the style of the restaurant for instance.From what you describe shiplap does not belong at all Think industrial /glam if anything certainly not rustic IMO. Posting some pics of your mood board might help too.

Was your plan for the ship lap above the brick? If yes, consider plaster or stucco instead.

Yes, that was my plan. See attached rendering...this is what I came up with to join the rustic and modern vibe that my client is looking for.