It's a sit up and beg so DT shifters aren't going to work, I think I might have some bagged NOS Suntour flatbar shifters but think it's overkill for the bikeOur shop sold the Courette BITD and I'm sure it came with a downtube friction shift, maybe a Suntour powershift later.
Maybe go that direction?
No, I have some in any case but it would look out of place and honestly, friction shifetrs are never going to break or need to worry about cable stretch etc.