BellBoard

 2345
(3254) 69: -pp s-sp
(2354) Extent 1: sps-sps-sps(s)*
(3254) Extent 2: -s-p s-sp s-sp
(2354) Extent 3: as 1
(3254) Extent 4: sssp s-sp s-sp
(2354) Extent 5: as 1
(3254) Extent 6: p-p-ps-p-p-p
(3254) Extent 7: --s--s (2nd obs)
(3254) Extent 8: s--s-- (2nd obs)
(3254) Extent 9: -s--s- (2nd obs)
(3254) Extent 10: --s--s (2nd obs)

Start with 69 to end with rounds at handstroke thereafter
all extents end with rounds at handstroke.

(s)* Call s in place of the usual bob so that extents
2, 4 and 6 start with a single. Extents 1, 3 and 5 remain true.

Extents 2, 4 and 6 are unique to a backstroke start and cannot
be rung from a traditional handstroke start