As per my previous reply -
I'm not talking about foot operated parking brakes , nor even Mercedes in particular ; I just don't like having more pedals in front of me than I have feet for . The widely disliked FOPB , incidentally , is only fitted to a small number of recent model Mercs ( although older LHD ones had them as they were popular on the continent , for some reason ) .
To me , a FOPB combined with a manual would be a nightmare . Disengaging it when moving off on a hill is not a problem since the 'fly off' lever is hand operated - no different to any other car - but engaging it in the proper sequence : handbrake THEN neutral is impossible .
On the subject of proper proceedures , how many manual drivers bother to select a parking gear ? So many people leave their cars in neutral , relying solely on the parking brake , it beggars belief . The correct proceedure , of course , is to select either first , or reverse , whichever would cause the car to move uphill - on the flat normally first would be your parking gear . Of course in a SAAB or a 1920's/1930's Mercedes S , SS , SSK or SSKL you have no choice as the gearbox has to be locked in reverse before you can withdraw the key .
I've had two W124 automatics with FOPB and never found it a problem , just inconvenient having to shuffle right foot off accelerator onto footbrake then left foot onto parking brake pedal .
All my other cars , including a few MANUAL Mercs ( yes , I've had them - still own two : the Ponton and the Fintail - cloumn change manual with 'umbrella' handbrakes under the dash ) have had other arrangements : the W114 and 115 had the pull out handbrake lever on the right of the dash , as carried over into the W123 , W116 and W126 . The W113 had a 'conventional' handbrake on the left of the tunnel ( set up for LHD and a long reach ) ; W201's also have 'conventional' handbrakes in the middle as do R107's . I've also had a Hilman Minx with handbrake on the floor to the right of the driver's seat ! No matter where is is situated , a hand operated parking brake is not a problem , you certainly don't need 'an extra arm' as you shouldn't be doing anything else whilst applying/releasing it , other than holding the steering wheel with your other hand .