OK,I make it 19 Sea Harriers still in UK military hands when that list was complied. Some of those are museum pieces, gate guardians, or bomb damage repair training frames. Maybe you could get ten composite examples by mix n matching.
Thats assuming any spares are actually available - which I doubt. BAE shut down most of the SHAR support some time ago, with staff shifting to other roles or becoming redundant. They're not going to restart just for ten (at most) part-time airframes. Inital lead in costs would be too high - and the MOD would never pay.
Forget it WEBF, it really isn't going to happen. You'd do better trying to convince someone to get some hooked Hunters back into the air so that current pilots can get used to landings on a mock carrier deck (Does a training deck still exist at Yeovilton or Culdrose?)
PS apologies for calling you SAM, but I trust you appreciate its an easy mistake to make