I actually remember that one as I spoke with Foto at that time.
The LHD and RHD non-US
lenses have mirror shape pattern because the low beam casts more light against the kerbside (US is flat). See here
The other difference is that the stock H4 globe is used for both RHD and LHD - it is rotated by an angle to create inverted pattern.
To convert RHD <--> LHD mirror on 107, globe seat may be all you need to replace on the mirror (it is removable) and hopefully use one from the more abundant 116, or similar.
Additionally, new LED globes are coming much better nowaday and some can rotate in their seat making it all simpler.
I just got ordered H4 LED globes with clear shape as per ECE and previous reporting suggests that the light casting is by far better end more even (no shading that is observable). Seeing is believing, for the cost of less than decent H4's it is worth a trial. Worst case they will end up in my semi-project van Vito 638 at work which strangely uses H4 globe for fog/high beam and a separate H7 for low beam.