Polymer 80% AR lower with DOJ FMBUS number

[fintech]

I applied for two DOJ FMBUS serial numbers and received them a few days ago. I made two 80% AR pistols a few years ago. One billet aluminum and one polymer. When I applied for my FMBUS numbers I chose pistol and the materials of each. One aluminum and the other polymer. They did not get kicked back and I have two put serial numbers to put on. The aluminum one is easy. I'm actually wondering about the polymer lower. Do I need to embed some metal tag on it to put the serial number on or can I put the serial numbers directly to polymer receiver. I have read allot about this. Some say I need to embed a few OZ of stainless and some others say I'm exempt because I applied for and received a CA DOJ serial number. Hopefully someday knows because I about a month left to register these as assault weapons.

[Quiet]

11 CCR 550511 CCR 550811 CCR 5509
Persons Affected by These Regulations.
This article applies to the following:
(a) An individual who owns a self-manufactured or self-assembled firearm as of July 1, 2018; and
(b) An individual who intends to manufacture or assemble a firearm on or after July 1, 2018.

11 CCR 5510
Effective Dates.
(a) An individual who owns a self-manufactured or self-assembled firearm that has not yet been recorded with the Department shall:
(1) Beginning on July 1, 2018, apply to the Department to request a unique serial number to record the firearm with the Department. The individual shall submit an electronic application to request a serial number for the self-manufactured or self-assembled firearm to the Department before January 1, 2019.
(b) As of July 1, 2018, no individual shall manufacture or assemble a firearm unless the individual applies to the Department for a unique serial number prior to manufacturing or assembling the firearm.

11 CCR 5519

[Inlander Arms]

You should be ok with it engraved onto polymer since the serial numbers were assigned before July 1st. The stainless requirement will be for anything after that. DOJ will have the record showing it was done before July 1st, although if you wanted to avoid hassles down the road you could always embed the 3.7oz of stainless to avoid confusion with law enforcement. 3.7oz of 17-4 PH stainless will be roughly 2 inches long, 1 inch wide, half inch thick (gets you just over 4oz)

[MountainDew]

11 CCR 5505
Title and Scope.
This chapter shall be known as the “Department of Justice Regulations for Firearms: Identifying Information and the Unique Serial Number Application Process for Self-Manufactured or SelfAssembled Firearms,” may be cited as such and is referred to herein as “these regulations.” The provisions of these regulations shall apply to an individual who owns a self-manufactured or self-assembled firearm before July 1, 2018 that is not recorded with the Department of Justice (Department), and shall also apply to an individual who intends to manufacture or assemble a firearm on or after July 1, 2018. The individual in each situation shall make a request to the Department to obtain a unique serial number for the individual’s unrecorded self-manufactured or self-assembled firearm. These regulations apply to self-manufactured or self-assembled firearms made from any material, including wood, metal, or plastic, and made through any process, including those produced by 3D printers. These regulations do not apply to a firearm that satisfies one or more criterion of Penal Code section 29181.

11 CCR 5508
Firearms Not Affected by This Chapter Pursuant to Penal Code Section 29181.
The following firearms are not affected by these regulations and do not have to be recorded withthe Department:
(c) A firearm that was entered into the centralized registry with the Department prior to July 1, 2018, pursuant to Penal Code section 11106. Such a firearm contains a serial number or other mark of identification assigned by the individual who manufactured or assembled the firearm and reported the serial number or mark of identification to the Department so that it is on file with the Department.
(1) This serial number or mark of identification is typically one that was created by the individual who manufactured or assembled the firearm; therefore, it is not a serial number or mark of identification that was issued by the Department.
(2) This serial number or other mark of identification shall be engraved, cast, stamped (impressed), or permanently placed on the firearm in a conspicuous location.

11 CCR 5519
Special Requirements for Engraving, Casting, Stamping (Impressing), or Placing the Unique Serial Number on a Self-Manufactured or Self-Assembled Firearm Made from Polymer Plastic.
A firearm manufactured or assembled from polymer plastic shall contain its unique serial number on 3.7 ounces of material type 17-4 PH stainless steel. This stainless steel piece shall be embedded within the plastic receiver or frame upon the firearm’s manufacture or assembly.

So I could make a wooden ar15 lower and register it prior to 7/1/18 as long as it was marked to code?