Yes, I made a mistake. I meant to refer to Marconi's link. And when I copied and pasted it I did not copy the title of the article.
To Jazz's point, I do not mean to express frustration: it ought to be apparent that I work on my antennas to the point of frustration trying to achieve the best match. There is a point that accepting what can be done must be arrived at, esp if it is not of consequence between the goal and the result.
When I work on it the most is when I am building it myself. I have greater control over the mechanical design, so being able to manipulate the antenna is a perogative I would not have that level of control over with a manufactured antenna. In fact, just this week when working on an antenna of my own manufacture I changed the location of where I had my matching section, and I tossed out the current matching section for another modified version as I wasn't happy with it. On the other hand, I have a fist full of mobile antennas I did not make, and when I put them each on my vehicle on the same puck mount on the roof some of them I can get a better (lower?) match on than with others. Given the limits of each antenna there is a point that I can do absolutely nothing about it and accept what I can get. The antenna I am currently having the most consistent results talking DX with from the mobile is one that has the lowest SWR at 1.5:1. The other end of 40 channels is 1.7:1. I leave well enough alone and talk from coast-to-coast and over seas, too.
Do I want lower? Of course. Is it necessary? Nope. Would I run an amp like that? Yep, I sometimes do - 100/200 PEP.
Some of those antennas have tuned lower than that on the same vehicle - when on the fender, or when sitting on a different spot on my roof. It's that simple. In a given location with parameters in the environment and within the antenna you can't control you sometimes accept what is possible and get on with having fun.
If I can help I will, but it seems to me you already have a great antenna that can give you years of communications pleasure.