so sorry to hear about your Mom's passing and the grief that all of you are dealing with, especially your Dad. If the dealer she bought it from won't take on consignment, I'd suggest you contact local quilt guilds (and by local I mean within about 100 miles) and ask if they would get the word out about the Q24--and don't take it all apart before then as anyone interested in it will want to take it for a test drive--and then they can be responsible for moving it. That is how I bought my LA, and also all the thread, etc the previous owner had accumulated. On the thread--the deal I got was great--for every new,unopened cone of thread I bought at $5/cone her husband gave me the opened cone free--he made about $300 and got rid of lots of cones.
Getting the word out to the guilds about a sale that you plan on the fabrics, etc (I'd suggest just a 2 day sale to start with--you'll get many buying up fabrics like crazy) will also allow you to unload many fabrics, etc quickly. I'd suggest you use a set price by yard , maybe a tad higher for batiks, and bag up scraps less than Fat Quarter size and price them as a set price. Good luck--so very sorry you have to deal with all this.