: Does somebody know what logo stands for ?

The only "Racing Mate" I can find reference to is a racing accessories (gloves, race suits etc) firm set up in Japan by racing driver Soukichi Shikiba. He's quite a renowned driver there, having won the Suzuka 1000km in a Porsche 904 GTS and the Japanese Grand Prix in 1964 (though it wasn't a world championship event back then).

Presumably the latter win was in an 804:

From Porsche's earliest (and not that successful, bar a win for Dan Gurney in the French GP in 1962) foray into F1. Apart from their spectacular success supplying engines to McLaren in the mid-80s, F1 hasn't really been a happy hunting ground for Porsche - the less said about the Footworks the better...

Anyway, back to what we were talking about initially. So Racing Mate in Japan looks a good thematic fit for the Monza, being active in the 70s and selling racing gear but there is a problem with making that link definitive. See, the usual Racing Mate logo is a quadrifoglio (perhaps "borrowed" from Alfa but likely intended as a good luck charm):

So we have a mismatch there, but that M1 image I posted before is from a race at Fuji in 1982, so the Japanese link is there again.

Perhaps Racing Mate got into hot water with Alfa over the quadrifoglio logo and changed it into the version we see on that G5 M1 and the Monza at some point in the late 70s. That would make sense to me. It also seems possible that they would like a logoed Monza to offer alongside gloves, boots etc in their catalogues. So I reckon that probably is the link, unless anyone knows better?

Thanks to various racing and classic Japanese car forums for some of this info.