The M21 sealant is available with 3m detailers in lahore and karachi, but i don't think the rest of those things are so easily available. M16, M26, M105 (though thats useless for you, too strong cut) and m205 can be brought from pw members Ausl and MGK, they can arrange. but for such old cars, i don't advise changing the wax too often, things don't always go so smooth.
My reason to support M26 wax is that it has the least chance of disturbing the paint as it contains no cleaners or anythin. You have hands on experience with the paint so you can understand that these paints seem to give you feedback unlike the new clear coated ones.