I know this seats, I use them for long time! so, go in the texture file "parts\fox68_seatpack\textures", find recaro.png edit with photoshop or similar program, save the new texture with same name "recaro.png"! make back up of original texture!
I think it should be good!
with scripting it's more difficult because it's RPK file who determine what texture is applied!
I just see your topic on GOM! you try and that don't work... let me try I come back!