RS232 is not really inverted, as the TTL level signal in the past was an internal card signal (that was not supposed to be exposed to the outside world). So really, it's the TTL level signal that is inverted!
It's no different to arguing that a non-inverting buffer is really a double inverter, because in practice, bipolar transistor circuits invert the signal by their nature in the most useful amplifier configuration (common emitter).
It is possible to reprogram a genuine FTDI chip to invert it's TTL RS232 inputs and outputs. But you are then restricted to that particular module. And if not labelled, could cause confusion at a later date. It is also not something that I have done, as it requires using software downloaded from FTDI's web site. Have a read of the datasheet if you are interested in this.