Help! Shimano hub gear for old Toba/50 cycles ebike

[dsearb]

The Shimano nexus 7 speed hub on my bike seems to have given up the ghost (36h rim brake, not roller brake)
I can only find nexus 8 speed units online
Anyone know if this will work?
I know the bike has a sensor which senses cable movement in the gear selector and eases off motor power during changes

Thanks in anticipation