Has anyone Matched the paint on 81 XJ550 Maxim or similar?

I just stripped and rebuilt most of my 81 550 maxim ( thanks all on here for the insights especially the carb. clinics ) I have it back together and running like a top and at the final stage i.e repainting the gas tank to finish up.

What I am after is a color code for this bike there does not seem to be one on the stem label and with the 9 digit vin it is not in there either (5k5008838) , I also don't know if this is a single or dual layer paint, type of top coat, etc. , etc.

I would actually prefer some metallic silver flakes in the new paint job ( think that would be cooler then stock )
but stock color would be very good at this point.

We don't have any good walk in paint shops in town at this point in time or I would just go that route Rollie- Williams used to be my go to for that, now they don't do custom mixes anymore for automotive.

Attached is my tank and side panel pic .. just like many others I have seen here (except for the rust and ding ) , The light makes that look a lot lighter then it is the side panel is the true(ish) color

..and yes I will eventually polish those rusty nasty looking head bolts .....