The present Ferlach gunmakers, enjoying an almost legendary status in some circles, are much overpriced IMO. As an example, a few years ago I asked Hambrusch how much would he charge me a field grade combination gun and he replied 24,000 euros

I went another way and bought a similar if slightly used gun for 1/10th of the price

So if in Your shoes I would frequent Viennese houses such as Dorotheum and Springer's and try to find a suitable pre-owned gun there. The saving would be more than enough for any modification needed, including re-newing and even re-stocking.
As I'm not that far from Vienna you are invited to see my Ferlachers (& etc.).
With kind regards,
Jani