The stenciling at the cowling, was not about Fuel Grade, as you can see at this Picture from the same aircraft.
The stenciling at the cowling is to read "Dirty Dick"
http://www.abload.de/img/azhspitfire0fg3.jpg


And for your special interest, a later Spitfire with the same Squadron Code AZ-H AD203 was also shot down over France, as you can see in the Pics below.
http://www.abload.de/img/spitfireazhmf40.jpg
http://www.abload.de/img/spitfireazh1uc13.jpg

The only Spitfire i know of, which was fitted a Daimler Benz engine was
Spitfire Mk.Vb NX-X EN830, 131 RAF "County of Kent" Sqn.

http://www.abload.de/img/hdbspit_12t13.jpg

EN830 Spitfire Mk.Vb (Merlin 45)
TOC/RAF 1.5.42
No.131 Sqn force-landed on Jersey after air combat 18.11.42 (P/O B. Scheidhauer, Free French Pilot)
Sent Messerschmitt factory Augsburg and to Stuttgart-Echterdingen in 12.42 (test flown by Willy Ellenrieder)
Armament & radio removed, 24-volt electrical system and DB601 engine installed
To E-Stelle Rechlin, marked 'CJ+ZY';
Comparison trials with Bf 109G in 1943
Technical failure 27.4.44
Destroyed on ground at Echterdingen by an USAAF bombing raid on 14.8.44; Wreck scraped at Klemm company Böblingen.

NOTE: P/O Scheidhauer took part in the Great Escape, but was recaptured at Saarbrücken, and shot dead by the Gestapo on 29 March 1944, along with 50 members of the Escape.

Ok, So if the Rechlin tests were definitley on 10th August then it can't have been any of these Spits. All were captured later than then.

So... What about the 'French' Spitfire? Thought destroyed but then turned up later in the war marked FW-8 (Captured 18th June 1940)

It's one of only 2 Spitfires I can find that was captured before 10th August 1940.

The other one being K9867(?) which is listed as FTR (23rd May 1940) in Shacklady/Morgan but Kurfurst has posted elsewhere that it was captured.

Either way both of these machines had 3 blade, 2 Speed props.

Just a note, the telex message (from LW HQ) is dated 9 August, and it informs various Luftflotten about the results of the trials and gives tactical tips to troops, but the the trials were very likely to have been conducted some time before that, as it has to be written down, and go through some levels before sent out.

When Rechlin actually did the tests, that's a good question.

I think it might be THE question..

It's your area so I'm hoping you'll (Kurfurst) dig something up. I know practically nothing about Rechlin or what they did.

Also it would be nice to try and find out what date W Molders uttered his famous 'miserable fighting machine' comments. I've seen it being quoted in as July 40, which would fit into the 10th August for the paperwork..

This is interesting because the further back the date goes the chances of it being 100 octane decrease.

This spit looks infinitely cooler than the run of the mill.

Sorry the report I have on my site is the only thing I have on the matter, but it would be interesting indeed to identify the aircraft that were tested there.

A for Rechlin (Eprobungstelle Rechlin - Rechlin Testing Station), it was Luftwaffe's/Imperial Air Ministry's own 'state' testing centre for aircraft of the Luftwaffe, basically everything the Germans decided to operate went through here first. They tested and evaluated new aircraft (ie. Bf 109 and He 112), gave their opinion on their relative merits, and were also instrumental in 'bug' fixing of standardized designs.

E'Stelle Tarnewitz was responsible for aerial weapons testing IIRC.

Re-checking the LEMB forum, I've found the following post... so, pick the most symphatethic Spitfire! ;)

The following images and paraphrased text are from 'Spitfire at War part 3' by Dr. Alfred Price. These photos were originally posted on the old LEMB by Jerry Brewer; the photos have since been rescanned and are re-posted here for further comment.

Spitfire ZP-J of No. 74 Sqn. serial K9867 was the first intact Spitfire to be captured by the Germans. This aircraft force landed at Calais-Marck on May 23, 1940 and was subsequently captured by German forces when they took this airfield.
http://i6.photobucket.com/albums/y23...ireMk1ZP-J.jpg

Spitfire ZD-A of No. 222 Sqn, serial P9317 was the second intact Spitfire captured by the Germans. This aircraft was captured by German troops on June 1, 1940 when it force landed at Le Touquet airfield.
http://i6.photobucket.com/albums/y23...reMk1ZD-Aa.jpg
http://i6.photobucket.com/albums/y23...Mk1ZD-Ab-1.jpg

The third intact Spitfire captured by the Germans was a PR 1B of No. 212 Squadron, serial P9331. This aircraft made a forced landing at Rheims-Champagne on June 7, 1940 and was later captured when the airfield was taken by German forces.
http://i6.photobucket.com/albums/y23...Mk1bP9331b.jpg
http://i6.photobucket.com/albums/y23...Mk1bP9331a.jpg

The fourth Spitfire captured was the only Spitfire delivered to the French prior to their capitulation. The two photos below show No. 1 after capture.
http://i6.photobucket.com/albums/y23...1french01a.jpg
http://i6.photobucket.com/albums/y23...o1tailfinb.jpg