I'd keep checking the lost and found a couple more times.
At DS's school, kids leave their coats all over the school yard and it could take a day or more to get to the lost and found. I'd even ask the teacher if that day when he lost it, if they went from recess straight to library or gym, maybe it was left behind inside the school. Check the cafeteria if he eats lunch outside the classroom.
I hope it resurfaces.
it's a nice looking jacket.
btw, I always marvel at how much clothing gets lost when I see the lost&found pile. From what I can tell, it's really common. I used to go to another school for playgroup with my pre-school DD and you wouldn't believe the pile there, it was larger than at DS's school even though the enrolment was smaller (!!). At that school, as in our school, once a year they'd spread out the clothing and invite everybody to go have a look-see to claim their belongings.
me:43, DH 44
DS: born by c-sec Apr15'03, 9lbs5oz 41wks gest. (after 4 years of ttc, starting in 1998)
DD born by c-sec Oct 13 2007, 8lbs13oz 39wk gest. (after just under 3 years of ttc)
~~DS was conceived naturally the cycle following a cancelled DE IVF, using my good friend's eggs. She was on the verge of hyperstimming.
~~DD's nat conception I attribute to using OPKs like a crazy nut, eating grapefruit daily and using preseed. also 5 cycles of TCM ending 2 cycles before that lucky cycle.