I always thought that the TB shirts were very slim? Also I havent seem many casual offerings - other than the OCBD.
BOO and Gitman Vintage 'look' to be the right shape from what I can tell - might give them both a go.
Depends on the shirt. I have a TB cord shirt that is a slim/classic fit (not the description just how it fits me) and have tried on the Oxford with grosgrain placket that was wayyy slimmer in the same size. They are quite long though. Your shirts fit well you could get them shortened at a tailor for cheap.
I know everyone (except some lame troll) loved that outfit but it just doesn't work; very dark leather jacket+dark tee with extremely light blue pants and beige boots is just a crime. Every piece looks good and fits well so it is just a matter of combining them differently but this is a no. I think it can work with a black top and white pants as it is taking it to the extreme and removing the black/beige annoyance.