(26 Jan 2021, 4:10 pm)V514DFT wrote I noticed it a few years back when the 57 Reg E400's used to be on the X21/X22, 9 times out 10 you wouldnt see a full allocation of 400s on there, you'd always get the renowns jumping in, and the likelyhood of it being 4510 or 4511 was very high, towards the end 4510 and 4511 were the worst 2 out of the lot,were literally falling apart, and must of had a severe leak somewhere cus they stank of damp,but were still seen as 'fit' to serve the public even after they left Newcastle/Northumberland, what i'll never fully understand is why 4512-4515 were the only ones refurbished along with the ALX300's,but ive since then found the answer, cus its Arriva,they do everything half arsed

4510 and 4511 were Newcastle based if I remember correctly so couldn't have been on the X21 X22. 4501 was also refurbished. 

I believe the Renowns were refurbished for the 35 quality upgrade back in 2012/2013.