In case anyone from Italy stumbles upon some old oscilloscopes branded as TELAV1 (sometimes misread as TELAY due to the horrible graphic design of their logo):
They are all rebranded Hung Chang oscilloscopes, especially the “TELAV 09635” (a rebranded “Hung Chang OS-635”) and the “TELAY 09620” and “AWS MODEL 620C”2 (both rebrands of the “Hung Chang OS-620”).