Might be picking up a FDE SCAR-17S but it has a Handl MK17 lower. I plan on keeping that lower on the rifle but I have a bunch of factory mags and I'm considering getting a factory lower as well. Can't hurt to have both I guess. Used is fine, and I see HDD sells "take offs" but they're out of stock. Also, any suggestions on where to find a parts kit for the trigger housing?  I'll toss the stock trigger in the FN lower and toss the Geiselle trigger in the Handl lower.

this is what you seek

OOS, and I still need to find the lower parts kit (minus trigger)

MGW has been out of stock for a loooooooooong time. They also have complete lower assemblies.

Gunbroker is another option, but I find them to be more expensive there. There is also the EE where people dump OEM parts after upgrading to the HANDL or Stryker.

There's also Hi Desert Dog might have parts, but I'm always skeptical of whether they are offering factory FN parts versus their in-house parts.

I think you can call the Browning Parts department and place an order. There may be a backorder but I have read that they will take your payment info and ship out when they finally get it. This is probably the best way to get the best price and guaranteed factory OEM parts.

This is the closest i've seen on the EE lately. A little paint maybe?
https://www.ar15.com/forums/topic.html?b=7&f=47&t=1491656