From what I can see c1 is the paraffin we used to buy as Esso blue, c2 is the 28sec heating oil. C2 seems to be an 80% mixture of alkanes with carbon chains of 9-21, the rest are branched chains or simple aromatics. From this I deduce the c1 is a mixture of similar but shorter length chains of carbon.
What I still cannot fathom is what the glowmax Total Butler advised we changed to, when their basic 28 sec heating oil started causing coking problems in our rayburn, consists of.
We changed to gas about 2 years ago when BG offered a low price to connect to a medium pressure main. The interesting thing is that although I ran the plastic tank down and there is only a breather the oil level has dropped a couple of inches, I cannot decide if this is evaporation or a slight leak!
One day I may try a smoke point test, petrol should give a longer chain than c1 paraffin and shorter still for 28sec then gas oil.
I did in the past try this test on resin bled from pine trees, I had been asked why lamps using this in Nepal were so smoky and it was because the trpenes have such a short smoke point (and the products of incomplete combustion were quite nasty).