Landships II

The reply is - sort of recycled WWI. To explain, there were still a significant number of lFH105 M16's in modernised format, but when German remilitarisation went open they introduced a "new" 105 Howitzer. The "new" 105 was a tinker on the old (aka m1916) howitzer - lengthened for a bit more range (here care is needed that sources "measure" the same way as length in calibres can be calculated in at least 3 common ways) & a marginal redesign in shell (mostly to take out WWI margins for production by non specialist companies). This is true for a great deal of German WWII kit, but particularly the artillery. Then there is the fact that German equipment scales & rosters are such a mess & hodge podge of other peoples kit (either because it was better or normally because they plain didn't have any where near enough!). 

As far as I can tell the only WWII nations to fundamentally overhaul their artillery are the US & Great Britain (including the domminions etc). The Italians & French are particularly bad at retained WWI kit for their artillery. The Russians update a lot & produce newer models but basically fight WWII with an artillery mix that was the ideal design format from the pre WWI Tasrist rearmament reforms. They do however introduce a number of pieces that a fundamentally new - its just they are so big an army that the revamps & tinkers don't get out of the system until post WWII.