I've got a tentative entry in and will see how things are in the next couple of weeks.
My first 600 and audax and on fixed! What could possibly go wrong? 
My tentative entry turned into a proper entry and I did ride the Flatlands on fixed. In that previous couple of weeks I rode quite normally, which means that I didn't do any training for the ride and the longest I did ride was 140km. But I did ride every day, which is normal for me, although some days where quite short, 16-20km. Average distance was around 40km per day.
I set my Garmin Edge 605 display to the map screen and followed the GPX file for that particular section and let the pink highlight guide me or would have done if Tomsk hadn't been leading us
. On the Edge I also had displayed average speed and distance to next turn. The average speed for the first four sections was in the high end of 25kmh after which is gradually declined to low 20kmh. I think overall the average speed, moving not including stops, was around 23kmh.
I lost all track of time and distance on the ride very early on! I don't have a watch and rarely flipped the Edge over to read other data whilst moving. It was surprising to suddenly turn up at controls after X hours of riding. I think next time I'll add speed and time to the map screen as well.
If it wasn't for the other riders who used controls before me I would have failed, I kept forgetting to ask for receipts and the sales assistants would ask if I wanted one. It isn't something I normally do but near the end I remembered to ask for a receipt from the control point.
After 200ish km I started to produce huge quantities of gas, which was also painful as it rumbled around my intestines! After this I had to use every toilet I could find, which was a lot, and de gas. I think it was a combination of wheat based products and exercise that made the gas. Experimentation, around the time of hitting Sleaford, by eating less wheat, basically meant not eating the toast that came with breakfast, I felt more comfortable and less gas issued forth at the next and subsequent controls. I didn't want to fart on the bike as it wasn't just gas coming out all the time.
The Pompino was fine for most of the ride. It developed a knock on left pedal stroke for the fourth leg but vanished for the fifth!?
Pedal revolutions in the area of >122000 strokes.
I was okay for most of the ride too. I was getting occasional numbness in my hands, despite moving position frequently and shaking out and flexing the fingers/wrists, and some in my gentlemen area. My palms felt like they were on fire on the ride home! The worst effect was at 400ish km my right shoulder had spasms and eventually this moved up my neck as well. This eased off at controls but came back, feeling worse, as the riding progressed.
Currently my gentlemen area is back to normal. My left hand at the finger tips and the heel of the hand below the little and ring fingers is still numb but going into a pins and needles situation. A slight numbness of right index finger is gone. My big toes, at the tips, were numb but normal now. My right shoulder is getting better but feels like it gets goosebumps and then goes numb or it catches a nerve and makes a painful leap for freedom ignoring that it is attached to the rest of me! No Achilles tendon problems but legs were a bit stiff, gentle stretching is the key there.
I've been riding but only short distances, <20km, and I think my first proper ride will be this Sundays SEG ride for a gentle 90ish km.
Thanks all for company and special thanks to Tomsk for the excellent route and the wheel. Although I did a bit at the front too.
I've yet to sleep in a bus shelter but really want to
They leave a lot to be desired! But after 22 hours of riding it doesn't matter and won't kill you.
TopTip: Take something to go underneath you. I had a fleece bag liner and bivvy bag which was too thin for the concrete floor and the cold seeped through after 20 mins! Huggy had a thickish sleeping bag and seemed/sounded okay!
