W123 Air Con What Do I do?

[man1nvan]

OK

I bought a lovely 300d manual whilst on holiday in Portugal, she was ckd South Africa and is totally rust free, lovely job..

However now back in the rainy cold old UK when i put the heater on , the windscreen mists up..

Easy i thought, rip the dash out of my scrapper and swap out the heater box..

but the new car has AC!! unheard of here in the UK, i have had 7 w123's and never seen it before,, only now i have the dash out, i have realised what a complicated setup this is. I have the simpler one with the white/blue dial rather than the buttons but i have a dilemma.

It seems a shame to rip such an awful lot of stuff out of my car, but it never really gets hot here, but on the other hand, how cool it would be to have working aircon (pardon the pun)

I know absolutely nothing about ac in the 123's is it worth trying to fix or would i be better off junking it?


PLEASE HELP A CONFUSED MAN

Also there is some oily stuff leaking from the centre heater box, initially i assume this was just antifreeze, but can anyone tell me if failing AC would deposit oily stuff here as well? (on top of the trans tunnel below where the radio sits) .
Also are the internals of the behr heater interchangeable between an AC and non AC setup?

TIA