[David]

The 15cm M.14/16 Haubitze was one the Austro-Hungarian Armys most numerously used guns during WW1. (The other two was the 8cm M.5/8 Field Gun, and the 10cm M.14 Field Howitzer.)
Although the Artillery branch was critically under-funded and equipped with a number of rather obsolete types at the outset of the war, many of the new pieces that eventually came to be used by them were in general very soundly designed artillery equipment, ranging from the famous and feared 30.5cm M.11/16 mortars - used by the Germans to breach the belgian fortresses around Liége - down to their versatile Skoda 7.5cm M.15 mountain gun.
This 149mm Howitzer (designated "15cm": the Austro-Hungrian Army always rounded off the fractions in the calibre designations: thus their 7.65mm M.8 Field Gun was designated as "8 cm") was another fine design, and although a bit short in range, it was used with effect during the whole war. It had a weight of some 2.76 tons emplaced, the barrel could be depressed minus 5 degrees and elevated plus 70 degrees, and it could fire a 42 kilo heavy grenade som 7.9 kilometers.

Its other drawback, beside the range, was that it had to be dismantled into two packs in order to be moved great distances - a drawback it shared with many other heavy guns of the era. The general soundness of the design was proved by the fact, that affter the war the Howitzer was adapted by the Italian Army - who had captured a lot of them during WW1 - as the Obice 149/13, NOT to be confused with the Obice 149/12, that was a pre-war gun made by Krupp, and built under license in Italy - and also by the Hungarian and Czech armies: so the gun saw action in WW2 as well.
This surviving Feld-Haubitze M.14 can be found in the excellent Heeresgeschichtliches Museum in Vienna. The colour does not appear to be the original, but rather a relatively new layer of pretty thin brown paint over a darker base, creating at places a rather streaked appearance.

This surviving 15cm Feldhaubitze M.14 can be seen at the big War Memorial in Redipuglia, outside Trieste: