Joe, I just got my 39MB back from a Keystone Dealer after having both the rear and top seal replaced under under the two year warranty. My slide was not properly aligned from the factory (too far toward the back) resulting in the slide ripping the seals. It was a 5 month ordeal getting the right seals from Keystone (long story I'll post later). If your seals are like our 2017 39MB they are hard extruded plastic and have both the inside and outside seal in one piece. Problem is they cannot be coiled or rolled up so they are extremely expensive to ship. I did locate them on Tierra RV's website, look under Redwood and you should be able to find them. They came in two or three different lengths which probably cover most of the RedWood slide lengths. I also learned the same seals are used on the Keystone Laredo which means they are not exclusive to RedWood so once you identify them you may be able to locate them through a local dealership. However if you are still under the 2 year warranty, I'd be calling Crossroads (Keystone) customer service and have them source them to a local dealer for repair. The dealership we used in Cody Wyoming replaced them in one day but we left the slides out overnight to let the silicone cure. We're on the road until Saturday, but if I can help with more info just let me know.
I'll be doing ours shortly. I have a small tear that needs to be replaced. For now, it's Gorilla duct tape to the rescue!
There is a United RV here in Fort Worth that sells all the rubber seals. The hardest part of the project will be getting the old silicon off. Then, remove the track. Then, cut the existing seal. Redwood used a seal that is in an "H" pattern. It is stapled on the inside of the slide. You won't be able to get it off. So, replace the wiper seal and then install the track back over the rubber seal. Then slide the bubble seal back in place. Finally, re-caulk everything back in. If I am going to do this, I'll replace the entire seal around the slide.
I have some pictures but I'll need to locate them tomorrow and post...