Planned Luftwaffe raid on Lincoln, August 1943?

Does anyone have any info please on a large raid the Luftwaffe may have intended to launch on Lincoln in August,1943? Seems they planned to attack the Ruston & Hornsby works with 55 x Do215s, with target marking by a trio of Ju188’s on possibly that type’s combat debut. Fortunately the attack never materialised (for whatever reason) and considering all the engineering works in the city, Lincoln perhaps escaped relatively lightly in WWII. Thanks for any further info. This is about all I’ve found so far-

http://forum.12oclockhigh.net/archive/index.php?t-20929.html