I have not seen one that has a true lawrenceanum shape. All looked like a hybrid and very obviously so.
The leaves in that old painting looks rather vague, though. A photo-like painting with exact details would have been more helpful.
The two I posted as screenshot do have a lawrenceanum shape so far, but they are long gone...
If you look in the AOS awards, you already see some AM HCC on hybrids as lawrenceanum hyeanum. One is clearly a big clump of Maudiae too with a CCM.
As for where to find it, it is easy. Nowhere. lawrenceanum hyeanum is completely extinct in cultivation, and no one has it anymore anywhere...
The problem was the flood of seedlings sold with 'Tradition' as a parent, or with some of the fast growing awarded ones that were those obvious Maudiae... The real ones by all account were very hard to grow. The German grower who got a real one is a superb grower, but he could not keep it alive. And it had typical lawrenceanum leaves.
Looking on Google, there are as well some hybrids sold as coloratum lawrenceanum around.