According from Das Ehrenbuch der Deutschen Schweren Artillerie and Der Weltkrieg 1914-1918 at the outbreak of WW1 in German fortreess there were 32 Versuchs-Haubitzen 99, but I was not able to know anything about them.
This is from a French site on WW1 German Artillery:
In 1895 the Krupp 15cm howitzer was adopted. It had a breech with flat corners. An order was issued for the urgent improvement of this howitzer. By 1897 APK (Artillery Testing Commission) was already collaborating with Krupp and the AKB (Artillery Construction Bureau) with a view to building a 15cm howitzer with recoil. Two years later the Versuchs-Haubitze (Experimental Howitzer) 99 was proposed. It showed promise but was eventually rejected as too heavy.
I have some research on the 15cm V.H. 1899 posted on my web site under "Development of the 15cm".
www.lovettartillery.com
There are several of these 15cm. VH "99 still in existence in the US, however, this has not been a piece I have tried to get because it was not in general service. I have all of the 15cm. s.F.H. series that were in general production (sFH 93, sFH 02, sFH 13, lg.sFH 13 with my example of this last one being the lgsFH 13/02 variation. You will see my research on these as well as photographs of my restored pieces on my web site.
