I looked around for explanation on differences between range of IQ scales and hence I was still not able to understand it fully I decided to build my own tool to convert scores from different scales.

Take a note that RAPM/RSPM/Otis-Lennon means and standard deviations were taken from this paper. For RAPM I adjusted them so they match my result, maximum possible result (185) and the information that I already found online (for example in this question).

Any feedback is more than welcome!