i could probably size down by 1.5 for the forest, but epaulet doesn't stock smaller than uk7 unless it's a special order or mto. the robert last is slimmer and fits better on me for the same size. the mto's i just received are on the rain and queens, but i haven't had enough time to break them in on carpet, so i haven't worn them outside yet. all four lasts are size uk7.
i've seen smaller sizes at the armoury and carminas eshop, but i haven't invested in the sizing experiment yet. pm me if you have any carminas on the forest last in uk6.5 that you're willing to offload.