Here is a video demonstrating the problem with the motor. Since I was unable to diagnose the exact cause of the problem, the easiest thing to do was to replace most of the motor using this donor unit I found on eBay last week.

...

Underneath the top bearing cap, a lot of fluff and carbon dust has accumulated, as usual!

Having removed the bearing, I washed the bakelite cap, then reassembled it all.

Not out of despair! I got the brush holder jammed under my thrumb nail :(
Still, no pain, no gain!

...hope I can remember where they all go!

The 960 differs from the 160 in that it has a larger dust bag, and a lined fan chamber, like the earlier commercial machines.

...

(From my 160!)

Cleaned, and with the smashed lightbulb-holder replaced with the one from the 960's original motor.

Up and running, in video and picture format!

and how perfect you've got a machine to clean up after the hordes of Christmas guests! There's something a bit growly about these machines I love.

Just mind those fingers! When I saw you insert them into the nozzle to start the 960 I cringed! And as for the bloody fingernail shot, what can I say but "Rivers of gore! Rivers of Gore!" I'll have to get you into John Waters movies...

I'm already a fan-in-embryo, I've read a lot about his films, and I've seen Hairspray (yes, the original, thank you very much!). 'Pink Flamingoes' is on my 'must see' list...

The 960 was the commercial version of the 160 in Europe. It took over from the 925 in 1938-39, then was made post-war 1947-48, before being replaced by the 912 in 1949.

In the US, you had the Model 90 after the 925, I believe.

The only differences between the 160 and 960 were that the 960 had a larger bag (for the filtering of a greater volume of office or hotel dirt!), a lined fan-chamber (see above!)and an all-white headlamp reflector plate, rather than the half-white, half-black one on the domestic 160.

Oh, and they did away with the fabric bag strap, using a spring instead - although I don't know if that applies to all models, or just post-war models, as I don't have any information about the pre-war 960s.

21,941 of these machines were built over a two year production run, from January 1947 to July 1948. My particular example dates from March/April 1947, making it an early-ish post-war example.

then you must also see "Desperate Living."

Edith Massey, one of his 'stars,' moved to Venice Beach in the early 1980s and ran a thrift shop there for a year or so until she died. A friend took me there once. There were no vacuums.

It would have been fun to own a cleaner from Edith Massey's thrift store, even if it was something totally unremarkable!

There is a scene in "Female Trouble" where Dawn Davenport is sitting somewhere with a Constellation in plain sight of her. Could the Magic Screen Capture Elf maybe dig it out and post it?

The earliest is on my 160, a pre-war version, made in '38 or '39. Crest underlined with the words, 'By Appointment to the Late King George V'.

King George V died in January 1936.

...is the crest on the spare 160 motor cowl which came with the set of parts I won on eBay. This simply says 'By Appointment'.

Is my 960 cowl, dating from March/April 1947: 'By Appointment Manufacturers of Electric Suction Sweepers'.

From the 160:

Notice this one has nothing engraved on it! A factory error?

I wonder if the one on the 960 is a replacement part? The theory being that the engineer should have stamped the details on it when it was replaced. I suspect that's why it has blank panels instead of the ratings being part of the design.

That could be a possibility, because there is a factory service date or code stamped on the underside of the chassis. Looks like it had a hard life, even the (possible!) replacement hood has a little damage to it at the back, and the handle ratchet mechanism is broken. Not to mention the previously-dodgy motor! All I know of it's history is that it came from a large farm house in Devon.