Cold formed joists circa 1960

[Struct1206]

Does anyone have any information regarding cold formed shapes from the 1960's? We're doing a hospital addition/renovation and the existing roof is framed with I-shaped, cold formed joists. I've never seen anything like them and can't find any info on them. Any info would be appreciated.

Thanks!

 

[KootK]

Is an I-shaped cold formed member even possible given that these things are break formed from flat sheet? Maybe back to back C-shapes or very light, hot rolled members? Trusses?