Technical Speedway Duval frame

Does anyone know who is casting the Duval style frames for Speedway? Looking to confirm if they are pure cast br*** or a br*** alloy. I need to weld on one and want to choose the proper compatible rod.

Thanks
moose

 

Bronze from the looks of mine. Silicone bronze maybe.
PM Dirty Doug. His buddy makes them in the great white north

 

Last I checked they were no longer showing them in their catalog, and only showing the 35/36 on back order?