2d It's like horn, made from a little hair and stuff (7)
13a Take earth stain off the mat (6) RE?O??
25d Wild antelope mostly caught by sawn-off gun (7) ?I????E
1a Madman in Austin briefly used to shoot down Jews (4) ?LA?
1d Outside the castle what may debag invasion force (4) ??SS
10d taken aback by surprise repeatedly, commonly takes pear (4) ?SES
1A is FLAK[E] "brings down jeTs, not Jews
1D is FOSS, I think, which would "debaR" invasion
Still thinking about 10D
Would appreciate help on 26A and 27D
Thanks for those. There is a misprint in 4ac : it should be "fOrmer" not farmer. in 12ac "males" should be "mUles". These give you "top" and "up" and the third is "strange" but I can't find the G and E yet. Following on from last week these are all types of tiny particles. The quotation is from the source of the name of these particles.