Prussian Unit: insured parcel accompanying letter as military official matter from of the federal fortress Rastatt at the company Boecking in adventure cottage with on face yellow package accompanying slip of paper \"Rastatt\". Reverse stamp seal with Prussian crest eagle and \"artillery DIRECTION of the federal fortress RASTATT\". This scarce letter to the ammunition factory in adventure cottage by Birches field is one of the few so far become known covers from of the federal fortress Rastatt and seeming the only accompanying letter for parcels, provenance: 299. Heinrich Koehler auction 1998 / lot 7067 (former starting price 150)