Fitted Kombi Seats Change Vo5/insurance

[ph1l1]

Hi
I’ve just got my kombi seats 2+1 fitted to the rear of my panel van, with strengthening plates and seat belt reinforcement plates etc. I told my insurance company and they want to see an engineers report. Anyone know who would do this?
Do I need to change it with DVLA?
Thanks

 

[ph1l1]

Oh and also want a certificate of conformity.