I loved the TR6 wheels on your A352, Mick, they really looked the part.
The issue with 15" wheels on the Sammio was actually clearance on the inner rear wheel arches - anything bigger than 175/80/14 with the added width of the wire adaptors would make the tyres foul the inside of the body on every bump. and widening the arches would ruin the look of the car (imho). That's not an issue on the A356 as the wheel areches are much wider to start with.
Kuba, I'm sure you can get adaptors to fit Jag wires to almost anything. Try Midland Wheel Services (MWS) -
https://www.mwsint.com/site/cms/cont...sp?article=684
I'm sure they do blank adaptors that you can have drilled to your own PCD.