If you insist on the both of you applying as a unit, then you can state it this way:
Dear Mr Smith,
The partnership of ____________ and _____________is writing to re-apply for the position of Assessors with your firm. We previously worked for BT by Adecco in 2005 and 2007. We are currently looking for interesting and absorbing work and would be more than happy to discuss any openings within the Assessors team.
We have attached our CVs for your consideration and are available for interviews after 4pm. We look forward to hearing from you. Please use either contact number given.