Question: Rear seat belt config.. '86 Komet high top

[HarryMann]

Hi, asking for a friend.. seriously 

Do they need to adapt to another central lapbelt, this is just short term for friends.
How would you configure this kamper for 3 children about 5 ~7 years of age. Currently on shoulder and one lap belt.
Could we use the lap belt for two child seats, are child seats mandatory for under 7's ?

Many thanks, picture below

[RogerT]

Here’s the law
https://www.gov.uk/child-car-seats-the-rules

looks like car seats are needed. Lap belts probably ok. Not read it all…