Glad you got a 250 as I do cringe when new posters turn up and say they have got a great looking IS220D!, it may be great looking but stand by for grief!
Best of luck with your 250 ( you won’t need luck with one of the most reliable cars out there!) As for trying to change infomation systems between models then I believe it is quite involved and not straightforward.
You say you have the ‘Older’ style centre dash, do you mean the non-Sat nav/touch screen version?
like this…..
oh yes and best colour😀