Hi SCP,
I have converted styles from various mades & models -especially ones that were made for specific songs-but I use more the SMF to style function to get exact the style for the song I need.Of cource always some 'remixing' is nessecary -particurarly on dynamics.As I mentioned before the Wersi supplied sounds are very very good so my addition of VSTis was done -apert from the experimental side-to cover specific sounds that are not available on my set (e.g.ethnic instruments).All the instrumental sound you are refering in your post are very well covered in the OAS instruments.
The basic Icarus configuration includes a tonwheel organ software module (Creamware?) that is controlled in real time from the front panel sliders.The NI B4 can be installed in addition.I dont know if these options give you the classic 'Wersi-organ' sound apart from the B3.
OAS 3.30 had no restrictions concerning different PC hardware.It requires of course certain hardware components to be present -with the proper activation codes-like the DSP cards etc. I have heard lately that a 'Hardware PIN'soft-button has appeared on newest versions ,so probably they now lock the whole thing together including PC configuration.
In any case I should advise someone to have the instrument upgraded and serviced by Wersi authorised technicians not only to save time but to ensure problem free operation.