IRC made some, I used to run GeoClaw lite (sub 500g but seem impossible to find new and least last time I tried to look) and Panaracer Smoke Lite are also lightweight tyres but not as light iirc (I have the weight somewhere).
That's hard bar a few quick wearing, thorn attracting, dry dusty track race orientated type with modern tyres even.
But if semislicks are your thing then modern maxlite, twister and fred would be light, but not amberwall.
Sub 400g in retro amber is probably the best you'll get. http://weightweenies.starbike.com/listi ... ortby=real
(but I do not know all tyres of course) I just know the GeoClaw where about as light as they got.
the more tread the heavier they are