Amperite ribbon mic

Someone just gave me this beautiful 1935 Amperite ribbon mic, to see if i could make work. All i was getting was some handling noise, which my limited knowledge told me it is probably the transformer malfunctioning.  I replaced it with a Shinhom T25 transformer, which is not too bad. it's a 1:36 trafo, but although it now works, the output is quite low (in a way normal for a ribbon mic, but lower than my other ones),and noisy (hiss). There is also  bad shielding as i hear some hum. I tried inserting a Cloudlifter, but it only exacerbated the problems. Does anyone have any idea as to what i should do to solve those problems?
Also, you will notice from the pics that ribbon is not corrugated. Have you ever seen that?
Thanks a lot.