The Naim Dac is still very good. I just bought an 11 year old NDac second hand. Together with the ND5XS2 it’s a very good combination at the level of an NDX2 but with a slightly warmer sound signature. There is a detailed thread about it(Click here).
I don’t know if recapping, which isn’t cheap either, is actually worth it for your components. An alternative would be to switch to Nait 50. It is a wonderful amplifier at a manageable price (there are also some special offers at the moment). And I also think that an ND5XS2 would be a good (and not too expensive) upgrade. You can use it as a very good streaming transport with Ndac. There is also a discussion about recapping for the NDac in the thread mentioned above. My NDac is currently working fine without service.