Hi Dan
I used GIS Mr.Color "Steel" whose number is C28. Although attached pictures are Akagi's machine guns, their color is the same as the color of the Yamato's machine guns.
I heard that TAMIYA paint series does not contain it. If you can not get GIS series, you can use mat-black with a very small mount of silver.
If you hope using this mixed paint, you had better try it on other materials before painting the sent parts.
I hope this helps you.
Best Regards,
Yutaro
Yutaro HONMA attached the following image(s):
DeAGOSTINI 1/250 the YAMATO, 1/250 the AKAGI.
Hasegawa Co. 1/350 Battle ship NGATO, 1/350 Aircraft carrier Akagi, Battle ship MIKASA.
Water line series 1/700 Battle ship YAMATO, HIEI, YAMASHIRO, Aircraft carrier HIRYU,TAIHO, Heavy Cruiser Myoukou, Ashigara, Nachi, Haguro & others.