That Durban Thai cross was labeled DTC99. It was a Durban Thai High Flyer from SSSC crossed by a C99 male. I have some of Mosca's version. A f2 cross of original BG seeds. Even Mr. Soul said that there is some magic in the f2s.
One should remember that Soul chose and selected his back crosses into the Princess. He used to talk of his "milkshake" method for doing so for each filial generation. He would mix the pollen from his selected males and dust the Princess mom. Then grow out that gen and do the same. In the end the last version was his P.97 version of C99 (5th bx). The P.94 version seemed to be the most stable version herein the seedlings all grew out looking like clones.
I read that, of course, he saved some beans of the P.94 version and that he selected a male from those spouted beans that looks like a male version of Genius to cross with his og Princess mom. Technically a new P.97 version of C99 but by a "selected" male instead of a milkshake mix. He said he learned how to better select the male side of the family. So the possibility of Mr. Souls C99 redux generation is as good if not better than og C99 is there. I will and shall get some more from them even at the high cost like back in the day. The classic fire or even better could be there. And I grown out and still have several og BG beans. And one Sly provided C99 clone only that I have shared time and time again. I want some new to mix with the old for my bank of just in cases...
BG lost half of the Brother's Grimm with Sly's departure. I knew Sly. He lived in my city and we got together from time to time. Back in the day when peeps were cracking 10 packs Sly was cracking and selecting from ten 10 packs and selecting from there. That is how he found his "Resin enhancing father" WW from Green House. The one Sly used for all his BG crosses mixed with WW. Sly also had other connects and made the Aurora Borealis , MTF, and others. Mr. Soul sent him cuts of his gear and the two made up the BG strain line. In the end Sly just dropped off the map. I heard stories but can not verify his demise or reasons other than the law coming down hard.