Disregard the following post I was able to find the 3M 560 in 10.5 oz and how ever many I want to buy. This is the only adhesive 3M recommends for RV walls because it stays pliable and allows some movement while maintaining a good hold. If you ever need any contact (discountmarinesupply.com)

I am in process of rebuilding the wall next to the door on the upper half. (dingbat owner before me didn't take care of leak around awning bracket), anyway the polyurethane adhesive from 3M is only available in a case of twelve. I will probably only use three of the twelve sausage packs. If anyone is in process of reworking an outer wall, needing adhesive, please let me know.
With shipping from the dealer it comes to about thirteen dollars a pack. These are 600 ml (aprox. 20oz) 3M 560. I will also have the cartridge gun necessary for the sausage packs, I think it cost me $43.00. If you are interested send me an Email ror007@aol.com Thanks Richard San Antonio, Tx.

I know you have already purchased the 3M product to do your wall repair. We used heavy duty liquid nails purchased at walmart. Others have used contact cement. It has been 1/12 yrs. since we did our big restoration and everything is nice and tight and dry.

Sam, thanks for the response.