John,
It was only a few years ago that a 40mm "C" Distagon was selling for around $1800.- second hand, quite a bit more than the current 250mm Sonnar. Point is, it's a very expensive bit of engineering so take good care of it ! Do hope you have the "T*" (multicoated) version which this lens uses to full benefit because of all that glass in the design. In my experience the coating is much less critical on the 250. Also, the regular 250 hood works very well on this optic and will save you the cost (and bulk) of the "prof." shade. DO, if you can find one, acquire a UV / Haze filter for that big front element on the Distagon: it's an expensive piece of glass and well worth protecting !
One tip: as these are older optics (and shutters), excercise the slow speeds regularly (1/1 through 1/15th) and put them away un-cocked at a low shutter speed. Again I use one second. I'm assuming you know how to cock the shutters before re-mounting. If not, STOP and ask ! Cheers,
RH