Amazing that the Bren Ten still has a following, and it is all due to a TV show. Boomer memories of a half century old TV show drive these sales. Without that media exposure, the Bren Ten would be a historical curiosity; it was a flash in the pan. Looked good, had a lot of very positive press. I still have a magazine issue on the introduction of the Bren Ten. The gunwriter had 200 rounds, wrote a long article absolutely praising the gun and the cartridge. The creation of the world was a small event compared to the introduction of the Bren Ten. He predicted a long future for the Bren Ten. At the time, never heard any negatives, or whiff's of production problems with the Bren Ten.
Forty years on, I can believe that Dornaus and Dixon were an under capitalized firm, probably living from gun sale to gun sale. The problem with Italian magazines not fitting production pistols is an example of a small shop not having on site Quality Control, probably they did not have face to face meetings with the sub contractor, may not have had a final drawing package. I can imagine the magazine manufacturer having an "as built" pistol to examine, and then the "as built" dimensions changing on the pistol production line!
Issues such as slide cracking indicate poor choices of slide materials, inadequate examination of slide stresses and heat treatment. These are all indications of a "wing and a prayer" development program. Having worked on "success orientated" programs, I can tell you, not having the time or money to research issues early, and then going forward with back of the envelope concepts, caused a lot of programs to fail. You see this all the time with Government programs.
Anyone looked at our Government mandated Green Energy transition? Typical example of a great concept that fails in the details. Originators who are "great visionaries", but lack the understanding of the logistics and development engineering that it takes to make "great leaps of faith" work, these individuals create expensive failures.
I am sure this is what happened with Dornaus and Dixon. Not having magazines to ship with their pistols was a clue that the company was not well managed, and was soon going to founder on the shoals.
As for owning one of the Bren Tens, if you shoot the thing and a part breaks, who is out there making replacements, and who is out there that can fit them? That is something a future buyer should think about.