Original: We are the only body who hold all the up to date authoritative information to complete the Con29R (Required) Form in full.
Simplified: We are the only body who hold all the up to date authoritative information to complete the Con29R (Required) Form in full.
Simplified: We are the only people who hold all the up to date  information to complete the Con29R (Required) Form in full.
Simplified: We are the only group who hold all the up to date authoritative information to complete the Con29R (Required) Form in full.