here a pic of one a friend of mine used to run also remember micheal o’ leary from liverpool had a fleet of 400,s & 401,s sleepers & day cabs also o’connors from widnes also had 401,s sleepers & day cab 201,s
A first for Unigate, away from Bedfords and Leylands.
I used to drive a Seddon Atkinson 401 Rolls Royce Eagle 265,Spicer splitter gearbox with a 6000 gallon tank on Shell doing petrol deliveries No.JUU 89W.It was a day cab and I couldn’t fault it for the job it was designed for.It had Alcoa wheels that gleamed and it was still going when I retired. Perhaps some were bad but this one was O.K. Regards,900X20. 
I had 2 400s, one was UGC 844W, ex Watneys Brewery, a sleeper cabbed 290 ■■■■■■■ with a full auto box, it was an absolute flying machine off the line & in comparison with the next one it was a joy to drive, but only in comparison to the next one 
This was a day cabbed piece of junk, CMM ■■?V, ex Lathams Timber, it had a Gardner 180, 6pspd David Brown box with Eaton 2spd rear axle, it wouldn’t pull a greasy stick from a dogs bum, the short wheelbase gave it an awful ride & I hated it, prior to driving it I had a Bedford KM & it was a 1000 times nicer to drive than the Sudden Accident, I voted on another post that it is the worst thing I’ve ever driven & that sums it up really. 
i had 2 as well mark 1 ex crockertons 250 ■■■■■■■ sleeper VHJ165S ok and 1 day cab exP&O tanks JAR~~~~V poxy motor that was had 3 301 as well as shunters still cheap cheerfull always got you home
LWN 834X was the 401 I had on Haynes out of Cornwall. It had the coach diff in it with the round the world nine speed. Until you got on the motorway you couldn’t use top gear. I was taking it to Edinburgh virtually every week in '94 when they were remodelling the mile.
The rivets on the crownwheel wore so it clanked, so the boss used high tensile bolts and it seemed to work.
You reminded me of the leaky windscreen. When the wind blew at it right, and the rain was heavy, you would get a fountain right in the middle between those rubber mats. The only truck I ever drove with a water feature in it!