Does the SP5 and SP5k use the same shelf?
No, they’re different shelves, see MM’s thread on the sear conversion he offers.
Since this is the official SP5 thread, I thought I'd show off my new "Case Club" hard case. It was about $185 and reminds me of a Pelican case. It has cutouts for various MP5 configurations and barrel lengths, and even space for optics. At the bottom left corner is a handgun cutout. The other cutouts allow for a total of twelve 30 round mags...as you can see I've put German flag stickers on my HK mags, South Korea flag stickers on my KCI mags, and the ETS mags are just there. I originally bought the collapsible brace but couldn't get it installed, so I swapped it out for the folding brace.
Finally got mine......Got lucky and found one online. Local dealer told me 6 months...