I think personally running Nandrolone around 600- 800 with test around 400-500 would work great. For the same reason you just mentioned. Now deca is no while near as anabolic as tren so you really need to load it up. I would do NPP if I were doing that otherwise the water retention from the long estered deca at that dose would be brutal.
I love NPP for older guys with worn joints its a must.