ID please?

I'm not sure, i've been searching for resembling photographs on the internet and in the Mammillaria Handbook by Pillbeam but didn't find a clear answer
For the first time flowering, 4 years old...and I lost the tag

My first thought is that it is a form of M. spinossima, perhaps the form also known as crassior? What do others think?

I go with Chris, a spinosissima form, but not a crassior I think. Crassior have muche whiter spination. This must be the form kladiwae. Deherdt nursery was selling this form for many years.