Funny but just yesterday I too was given the same thing!LOL I'm going to post pic's today!!
I think its best to put them together 1st!!it just seems to me they will have a better chance of holding up to the stress of washing and any other stuff you will have to do to get them clean!! If they smell you can put them in a box with a lid and put alot of Bakeing Soda close it and shake and let it set for a day or so so you can Sew with out the smell.:)