So now everything is clean and lubed ready to go together. If you want to change breech washer, now is a good time to do it while you have room to work. They take the rubber webley washer ,although Diana 23 I did had a thinner washer than other Ive done,(rounded side facing barrel) or make one out of leather by cutting round a small socket and putting hole in middle. I soak them in almond oil. When the gun is together you may have to keep poking the hole open for the first few days till it settles in. Replace your spring and plunger and nip up grub screw (till it locks plunger and then back it off) I had some 4ba brass bar and just cut a length of this and cut a slot in top for small screwdriver. Piston,spring and guide back in cylinder and then the sleeve (NEXT BIT TRICKY) push on sleeve with bar and socket and then turn it to locate on recess when far enough down. THERE IS A LOT OF PRELOAD ON THESE SMALL SPRINGS. Offer triggerup and replace pivot. Locate endcap and push in till you can just get trigger spring in and then tap home. Replace barrel and then cocking arm and then fit back in stock and replace sights. Ive seen a lot of these where the trigger AND/OR piston rod is worn--filing them square again will get the gun working but keep an eye on it for safety. God Im sick of this already. Diana 25/27 next.