From memory again, I have found that, by and large, paintings commemorating royal events are not very reliable for details of regalia and jewellery.
[I believe an exception is the Winterhalter portraits of Queen Victoria where details of her jewels can be relied on.]
Last century the various coronations were often commemorated by publications prepared ahead of the event containing illustrations only of what the artist "foresaw". Further, paintings after the event did not necessarily portray precisely what occurred.
Having said all that here is an illustration of St Edward's Crown "as it looked in 1685".
I'll just comment that there does seem to be more space between the edges of the crosses and fleurs-de-lis than there is today.

Edit: one of my sources says the front cross overlaps the flanking fleurs-de-lis these days!