ANO Schedule 7:
Privileges and conditions:
(1) Subject to paragraphs (2) to (8) the holder of the licence is entitled to fly as pilot in command of any SSEA, microlight aeroplane or SLMG for which a class rating is included in the licence.
SSEA class rating
(1) Subject to paragraph (2) and to the conditions of the licence in which it is included, a SSEA class rating entitles the holder to act as pilot in command of any SSEA with a maximum take off weight authorised of not more than 2000kg excluding any such aeroplane which is a SLMG or a microlight aeroplane.
Carriage of persons
(8) The holder may not fly as pilot in command of any such aeroplane:
(a) if the total number of persons carried (including the pilot) exceeds four
Seats are not mentioned so they are not a factor, so no problem with a Cherokee 6 if its under 2000 Kgs
Re the 10 hours I would hope you could include previous experience but that's not how its worded in the law!