First, good job getting to where you are now.
Second, let's talk about your form. When you squat, you're never standing up. Your hips and knees remain unlocked at the top. Stand up straight when you finish your rep. You are also over-extending your back and your elbows seem a bit high. Your stance is also wide, so you might want to bring them in about 1" each side and it will help keep your knees out--they started caving in as your sets progressed. Lastly, you're kinda doing this relaxed dip at the bottom of your squat. Stay tight all the way down and don't relax to hit depth.
Your deadlifts are drifting away from you each rep, and you're sitting back and dropping your hips (it's worst at the last rep). You're not setting your back flat and tight enough to start each rep. Squeeze all the slack out of the bar and get your chest up and fight to hold your back in extension as you pull.
Stalling
When I went through novice LP, I stalled at the same place you did--260lbs. I did what the book said: repeat the workout twice and reset if I couldn't get all the reps. That was hugely unproductive for me as I was missing reps due to lack of recovery. I was eating and sleeping fine, but after squatting 245, 250 and 255 three workouts in a row, I just felt a little beat up when I hit 260. My warm-ups felt much heavier than usual that day. What I wish I'd done at the time was switch to advanced programming (i.e. add a light day in the middle). If you knock out all the reps on your next workout, keep going. But if you stall again, switched to advanced novice programming and don't waste time resetting.
My press stalled at 155, and I switched to doing triples and pyramiding my sets (e.g. 145x5, 155x3, 145x5) to buy more progress as I microloaded my top sets. Eventually I stalled, did a reset, and stalled at the same exact weight all over again. Knowing what I do now, I wish I'd switched my press to 5x5 when I reset. I wasn't stalling due to fatigue or feeling beat up from pressing--I stalled because I just didn't have the strength due to lack of volume.
Deadlifts
If your deadlift is progressing well, don't kill your progress by changing things up now. You could probably handle deadlifting twice a week, but you could stall on that lift a lot quicker than if you just stick to the program.