I have been pretty confused about this ATF ruling on braces and trying to figure out what I should do, so looking for advice. I do I have trust I set up with Mark Zeck around 2012-2013 time frame if that helps in any way but the others were not bought with this trust.

What I have,
1. a pre94 ban AR that has been SBR’d and currently sits with a brace on it. Has a 8” 300 blkout barrel on it
2. 9mm AR I bought from the gun store a few years ago set up as a “other”
3. .45 AR same as above

I have a few rifles that were registered with the last bullshit ban but all of those sit with regular stocks on them so I am only worried about the three above. What would you suggest I do with them to make them legal, I have to much to lose by saying screw them, but trying to figure this mess out has challenged my understanding of it.

Why do you have an SBR with a brace? It can't be a pistol so there's no point. It's a pre-ban, so it'll either be grandfathered in or they won't mess with it.

The other two, who knows.

It’s a collapsing brace and I just liked the feel of it but plan on changing it back to a normal stock I think.

if it's SBR'd already you can use a stock, but fine if you prefer the brace better.  No one will care about that.

For the two "others" the options are:
1. Remove the braces (and get rid of them, the ATF said) and keep the buffer tubes naked
2. Get to 16in for barrel length if you want to keep the braces on.  Make sure the vertical grip stays on to keep it in CT "other" config
3.  File Form 1 to obtain "SBR" status by end of May, but you cannot really SBR them.  They must stay in legal CT "other" config

It's very important to also keep up with HB6667 which would ban prebans and CT "others".  And of course there are 2 active lawsuits against the CT AWB by NAGR and CCDL/SAF.   And don't forget the national lawsuits against the ATF brace rule.  A lot of stuff happening at the same time, and people are naturally confused.

Thank you, that is pretty clear. I used to stay up on this stuff but life/work has been busy and it’s been tough to catch bits and pieces of it.

Note what ATF's FAQ on their brace rule indicates with respect to Trusts:
https://www.atf.gov/firearms/qa/can-i-register-my-firearm-%E2%80%9Cstabilizing-brace%E2%80%9D-my-trust
Can I register my firearm with a “stabilizing brace” to my trust?
Yes; however, the firearm would have needed to be owned by the trust prior January 31, 2023. Evidence that the firearms was in trust should be provided with the registration document.

Note that the ATF brace rule is completly seperate from CT's AWB. You are supposed to comply with both. ATF has a bunch of information you can reference at this link. One can read SLFU's latest memo/opinion (see this link) that indicates one can SBR a CT "other" but it must remain in the "other" configuration. In other words for post 9/13/94 manufactured semiautomatic CT "others"; no "stock" and no barrel under 12 inches. Using either subjects the post ban CT "other" to CT's AWB.

As already said, if the preban firearm is already registered as an SBR then one doesn't have to do anything new to comply with the various laws and rules. For the "others" that are of post 9/13/94 manufacturer one has several options:

• Remove the brace or blade.
• Use a 16 inch or longer barrel.
• Register the "other" with ATF as an SBR. Just note that one still cannot put a stock or under 12 inch barrel on a post ban SBR since it conflicts with CT's AWB.

Further reading:
SLFU's initial memo on the ATF brace rule, see the other link above for the second later memo:
https://portal.ct.gov/-/media/DESPP/SLFU/ATF-Final-Rule-Memo_2-8-23_Final.pdf
Pay attention to what's happening to HB 6667 which, if passed, would classify "others" and prebans as assault weapons.
https://cga.ct.gov/asp/cgabillstatus/cgabillstatus.asp?selBillType=Bill&bill_num=HB-6667
See the earlier discussion threads that have further discussion including addressing most of your questions which have been previously asked and discussed:
https://www.ar15.com/forums/Hometown/Updated-SLFU-Memo-on-CT-others-and-SBR-3-30-23-/26-667970/
https://www.ar15.com/forums/Hometown/ATF-Final-Brace-Rule-Released-Update-in-OP-DESPP-SLFU-issues-guidance-2-8-23/26-666448/