Sorry for chiming in so late, been busy with my roof repair from Hurricane Irene.
Raid and Godfrey, the older 50mm C lenshood will vignette at the outer edges of your image frame.
If you have the original 38mm C lens-hood for the SWC, SWC/M, use it as it has a little lip to allow you to mount the correct Bay 63 filters for use with the hood.
The filter retaining rig will only hold the filter, and not include the hood. Its one or the other. I do not have the older 50mm C lens to test out this theory, but believe that it works similarly like the filter to original lens-hood setup as described above.
Its best to buy the original Hasselblad filters if possible. The 3rd Party vendors such as Tiffen, Hoya, Kodak , H & H did make Series 8 filters that will work on the SWC.
The main difference is positioning of the rear filter ring that faces in "near-contact" with the front of the 38mm Biogen front optical lens. If you have the original filters and compare it against the 3rd Party vendor, the portion of the filter that is flush with the filter ring must face the front of the lens and must sit in the3 front of the lesnhood. Don't be in haste and assume the filter will fit either way. THe seating of the filter glass flush up front allows the rear portion to have an "air distance" held in place by the actual filter ring. Look at the3 filter before you insert it into the lens-hood.
There were many reports back then of the front lens getting scratched or impacted by the filter. I bought my SWC from Ken Hansen Photo and remember Ken installing several of the buyers of this problem. I was on of those buyers. The SWC & SWC/M with the C lenses were sold by Ken Hansen whenever he got them in. Majority of the time it was sold out to the many young Japanese photographers to used it as a Point & Shoot camera.
I use an assortment of filters to supplement the original Hasselblad Series 63 filters. Majority of them are Hoya or Tiffen with MC coating. My SWC was converted to SWC/M when the upgrade kit was widely available for Polaroid back use.
Finders - I use the original finder as it is more solid then the newer OEM 903/905SWC finders. I have one of the newer finder for tripod use only. Not so sure of the quality of the Chinese made 903/905SWC finders on eBay.
As for straps, it was a choice of the thin leather strap, hand strap, newer nylon strap (I use all three) and the Domke Griper strap.
I use my SWC/M as a Point & Shoot when I travel overseas for medium format images. For all intend, it serves its purposes as a high quality camera.
Evan
If the less costly shade does not vignette, then I woud keep it. Maye someone who uses the hood on the SWC can comment on this issue.