I do not write appraisals, or certificates of any kind other then for instruments that I have personally made. This can be a hazardous area of expertise both in law and in reputation. Having said that, these instruments are stated as being made by particular makers based on existing certificates issued by established firms such as W.E.Hill, J. & A. Beare, Bein and Fushi, Wurlitzer, D'attili and others.