Hi ! I'm north Dorset and have a small flock, not as small as yours but a total with the ram and his friend, 15 although five at least shouldn't be here !! I get FEC done and my vet dispenses the amount of wormer needed. That doesn't help with heptovac although a near neighbour and I share.Had a word with your vet ,they may be able to help or put you in touch with another small flock with their permission of course.