Your best option is to tell them you need more T-Shirts to make a quilt. For a bed size quilt I use a minimum of 20 imprints in a 4 x 5 setting with sashing. A t-shirt wallhanging will not bring in any $$ for a fund raiser. If it is an auction very few will bid on it and the $ amount will be small. If it is a raffle, very few will buy raffle tickets for a quilt that is not even as big as a lap throw. I am sure they can ask the firehouse members/volunteers to try and donate more shirts.