SP10mk2: OMA Graphite plinth vs.Dobbins plinth

I have the original box and original manual for my Micro Seiki CU-180 which i am using now. There is a sticker on the box with model number and they call it "MICRO GOLD DISC CU-180". The manual is in japanese. 

Here is more about gunmetal:
Gunmetal is a type of bronze — an alloy of copper, tin and zinc, originally used chiefly for making guns!  Proportions vary by source, but 88% copper, 8–10% tin, and 2–4% zinc is an approximation. Gunmetal, which casts and machines well and is resistant to corrosion from stean and salt water is used to make steam and hydraulic castings, valves, gears, statues, and various small objects, such as buttons. It has a tensile strength of 221 to 310 MPa, a specific gravity of 8.7, a Brinell hardness of 65 to 74, and a melting point of around 1,000 degrees Celsius.

Fortunately, the ambient temperature in most of our listening rooms probably does not exceed 1000°C.

Dear @lewm : The original SOTA mat has not that " felt like material ". The SOTA mat was on sale as an after market mat and goes glued ( self glued. ) to any TT platter, in that way the mat is part of the TT platter and not changeable: it keeps fixed there for ever. Another very good characteristic is that its spindle center hole is small diameter enough for the spindle form part of the TT/MAT part. The mat has no " play " around the spindle even you have to push it with care but enough pressure to install it.. It helps to damps the metal spindle too. Was very good thinking item other than its undisclosed build blend material. Recomended.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

has anyone ever tried the Comback Harmonix mats?

 Dear Raul, the mat on my star sapphire series 3 was most assuredly the original felt mat. Perhaps the dealer glued it to the platter before he sold it to me, but for whatever reason it was glued to the mat, and the surface was a felt like material. Just for your information, it was only later, when I acquired much better sounding turn tables, that I discovered how muffled and recessed was the sound coming from the star sapphire, meaning no disrespect to current SOTA turntables. Even with vacuum applied.   The experience did not leave me believing that there was anything special about the mat on that turntable, except possibly that it was especially responsible for the unsatisfactory results. My next turn table was a Nottingham analog hyperspace. It ran rings around the star sapphire in every way. Even more so after I acquired a regulated power supply to supply AC to the Nottingham.