Not a sigelei but looks like the 19b http://ehpro.en.alibaba.com/product...ic_mechanical_mod_e_cig_GGTS_Mod_wonder_.html
Its flat Whit, but has a much more defined chamfer to it than the 19b. It would be a grind down on the head again, and it doesn't look like there is enough scope in the 510 for that.