2a. it contains a list of all references (sources of information), presented in accordance with the layout style guideline.
the "number built" figure in the infobox isn't supported in the body, Jane's says 86 in 1941, 1,350 in 1942 and 766 in 1943, these figures should be given as well as the total figure. Done
2b. reliable sources are cited inline. All content that could reasonably be challenged, except for plot summaries and that which summarizes cited content elsewhere in the article, must be cited no later than the end of the paragraph (or line if the content is not in prose).
While not necessarily OR, there a few discrepancies I hope you can clear up. Zaloga p.24 says the gun was the A5 variant, that the original gunshield didn't provide much protection for the crew, and provides a description of the gun adaption that would be a useful addition. He also says that it was accepted for use in the U.S. Army on 31 October 1941. These points should be checked against other sources (like Jane's), and compared and contrasted if different. Also, Jane's says the later mount was a M5 mount?
I implicitly stated that the gun shield lacked sufficient protection in one sentence. Otherwise, it's completely done.
its performance is mentioned in Hofmann (2006) Through Mobility We Conquer: The Mechanization of U.S. Cavalry, University Press of Kentucky, p. 310 Referring to its performance in North Africa: "The 75mm M3 gun motor carriage mounted on a standard M3 personnel carrier proved to be useless as an antitank weapon. Nonetheless, the M3 motor carriage was at the time considered the most effective system when used in battery by E Troop, 91st CRS for artillery support." Conversely, Jane's says they were acceptable as an interim measure. And Jane's says they were popular in the general support role with the British until the end of the war.
No mention of use by the USMC Done
No mention of the elevation or traverse with either gunshield, according to Zaloga, one of the reasons General Bruce didn't like it was its poor traverse. Both available in Jane's. Done
No ammunition capacity provided, but available from Jane's Done
3b. it stays focused on the topic without going into unnecessary detail (see summary style).
4. Neutral: it represents viewpoints fairly and without editorial bias, giving due weight to each.
5. Stable: it does not change significantly from day to day because of an ongoing edit war or content dispute.
6.Illustrated, if possible, by media such as images, video, or audio:
