GardenBanter.co.uk - Tecumseh Flymo Dellorto question

Hi all, newbie here. Just acquired a s/h 18" Flymo (it's actually a Crown, if you've ever heard of that--Google hasn't).
It appears that this hover has been used incorrectly, maybe for quite a while. The linkages and springs on the carb seem wrong, and the choke won't operate properly. It has been started by just pushing the control lever forward to "Start", but the end of the lever shies away from the choke spindle when released. Only way to use the choke is to hold the lever forward (difficult when pulling the cord!)
Pics of what there is at
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http://upmyphoto.com/thumbs/FreeUploadUser/p1010010.jpg http://upmyphoto.com/thumbs/FreeUplo...p1010011_2.jpg http://upmyphoto.com/thumbs/FreeUploadUser/p1010012.jpg http://upmyphoto.com/thumbs/FreeUplo...p1010013_1.jpg
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The mower as I say is designated "Crown", the label on engine cowling says "Aspera AV6(something)"...possibly AV600?
The tap on the tank says "Tecumseh"...and the markings on the carb are "Dellorto FHC 20 13". that's all I have.
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So the problem is the unit cuts out gradually when moved to "minimum", and the choke won't operate without pushing and holding. What I would expect of this set up is push forward to "Start" (operating the choke), then adjust speed to suit. The governor spring (marked in white for clarity) is obviously just a makeshift spring, stretched. The dimple in plate (marked "A" on photos) I would have thought would drop into the hole on the control lever WHEN ON CHOKE. Is this correct? At the moment it drops while pulling the choke OFF. In other words, the dimple DETERS operation of the choke, unless held by hand.
If no-one can help with htis, perhaps someone could point me to a PHOTO of this set up with the CORRECT springing. The minimum I need is a new Governor spring, but I don't know which one! Thanks