Oct 2017: I spotted a photo of a Speedwell GT on Facebook so copied it to Speedwell guru, Alistair Ross. He replied:

"I do have it (the photo) as it was sent by the chap in Sweden, Mr Jonas Lindquist who had spent some time trying to trace the car. This car(?) was take by Lutz Arnstien and wife to Sweden as a promotion for Speedwells and was sold there. There are several pictures of it racing in the snow and also a YouTube clip of it. Somewhere I do have a Swedish Motoring feature (in Swedish) mentioning Speedwells attempt to sell cars there. Attached is I think is the same car or maybe another in Sweden. I'm sure that Jonas could fill in some of the gaps?"
And sure enough he has:
" Hi Alistair and Martin, Nice to hear from you again! I talked to one of the owners of this car several years ago, Mr. Carrhage, and he told me that after the heavy crash during ice racing in 1963, the car was taken to a workshop in the Stockholm area but later destroyed in a fire in the workshop in the mid 60´s, and the remains of the car were buried in the ground somewhere (!?) Unfortunately he is no longer alive and it’s very difficult to have this information confirmed. I have tried to find out which colour the car had since the black and white photos available doesn’t give a clue, but it might have been light blue (?).
An interesting thing is that I once owned an aluminium Speedwell Monza front end which had some serious damage to the forward RH side and it once had a light blue paint, the aluminium front ends arepretty rare and this just might have been from the crashed car... During the few years this car were “alive” in Sweden it must have had a rough life, photos show different paint jobs but no colour photos have been found yet, unfortunately. This made me wonder if there might have been more than one Speedwell GT in Sweden but everyone I talked to confirm there’s only been one, and it is 728H/AA8155. What I found out so far is the car had three different owners during the short period in Sweden : P-I Brandström, Jan-Eric “Nenne” Andreasson and Sven Carrhage.  P-I Brandström had a company selling tuning parts called “Motor Speed AB”, Speedwell parts were one of the brands they had on their shelves. Jan-Eric “Nenne” Andreasson also had a company selling car parts called “BABEA”. Another interesting thing is that the registration number “728H” this Speedwell car had when it appeared on motor shows in Sweden was later used on a Lotus Eleven owned by “Nenne”, see attached photo. The only Swedish registration number used on the Speedwell car was “AA8155” and it was registered for the first time in Sweden 21st May,1962 and last record found is from an insurance company in 1966, I have a copy of the registration documents showing the chassis number, but I believe there’s no archive or information left from the time when the Speedwell GT’s were made? Hope this little bit of information is useful. Best Regards Jonas Lindquist, Sigtuna, Sweden".

Probably a different Speedwell GT bearing the reg no. 728 H was entered by Peter Jackson for the Sebring 4 Hours in 1961, its drivers being Richard Melville and Graham Hill. The car completed 33 laps (a little over half distance) but failed to finish. Peter says: "I think that Speedwell used that reg number on several of their cars, though I never had any dealings with them myself as I always dealt with Sprinzel. I still have the original scrutineering ticket from Sebring which has Graham and Richards names on it but no reg number for the car.I seem to remember Richard saying that some German  bought the remains of his car after he crashed it at the Ring."