We have an original Victorian bedstead with a replica sprung base, comprising iron frame holding springs and mesh that lays on bedstead. This base is 35yrs old , the springing is still in pristine condition with no sagging at all. Our current matress is Dunlopillo also about 35yrs old, which in fairness has served us very well. However, we are in need of a replacement . We are both about how 12stone. Could you advise me please.