Yeah, well, there was room on Holdens to do that. On 140s, there's the inner guard and upper wheel arch support that joins the firewall at an inconvenient place, which doesn't allow one to slap the booster on the firewall.
With the additional 4 or so inch gap provided by the LHD booster bracket to the firewall, it might be possible to fit a smaller diameter booster. A 240 booster is just too big unless cuts are made in the inner guard or upper wheel arch support.
If a booster cant be fitted in there, it may be case of doing something like an Amazon setup and remote operating the booster.