No, it's grafted. I got it from Esveld, I believe the source material was collected by De Jong. It's got an air of grandidentatum, but you wouldn't really confuse the two, seen side by side: they're actually only 10s of meters apart here. Funny seeing these early pictures, this maple has thrived and is quite a large and bushy thing now. I will probably have to raise it up a little, as I've never really pruned it.
I believe both acer ser. monspessulana and acer ser. saccharodendron have a common ancestor that eventually went extinct in eurasia. they appear to be the closest related, at least superficially by the droopy green flowers and samaras.
