Technics SP series mats?


Other recent discussion here discusses replacement mats for DD tables, including the SP series.  However based upon photos showing different ring patterns of stock Technics mats it seems there may have been a few different models over time.  The mat with my SP-10 Mk2A is SFTG172-01 while the mat with my SP-15 is SFTG015-01.  The ring pattern appears the same but the first one is heavier, thicker, and stiffer.

So does anyone know how many different mats were provided for the SP series and if any one is recommended over the others?  Perhaps more important, for those who have tried different mats did they offer sonic improvements over any of the stock Technics mats?  I realize this is difficult to answer unless someone tried more than one model Technics mat. 
pryso
S Bank, You actually put a 4 kg mat on your SP 10 Mk 2? The entire platter of an SP 10 Mk2 weighs something like nine or 10 pounds and of course 4 kg is nearly 9 pounds. so you doubled the mass that had to be driven by the motor and supported by the bearing. I don’t see how that could be a good thing, but of course it’s your turntable to do with as you wish.

Of course, putting a MS CU500 on a mk2 is similarly over the top, IMO. 
Lew, yes I did. Used it that way for about a year and a half before I sold it as I downsized for a relocation. Never had a problem. Our pal, dgarretson, gets partial credit / blame  :-) for helping me down that path.
Those who heard it heard how it could be a good thing. 
You can see pics here on the site of the man who made it.

https://vnav.vn/threads/tvt-analog-shop-chuyen-cac-phu-kien-ve-dia-than.30728/page-11#post-1426052
Cheers,
Spencer 
I use a Herbie's Way Excellent II on my SP-15 and its significantly better than the stock rubber mat. Seems like it would be worth a try on the higher end decks too.

Why rubber?  Agree with above posters.  Try a Cu-180, Cu-300, AF Copper, Tenuto, Acrylic perhaps.  Rubber just deadens the landscape in my experience.