Just measured an other one, this one is about 200. Looks much better. I don't think the transformers are an issue. I used them for a lot of measurements and they come from a high quality source. I also measured the Q with the scope using a square wave of 1 Khz and then measure how fast the signal drops to 0.707 V if you multiply by 4.53 you got the loaded Q.
The coils is 0.3862 uH (6 turns 1mm wire T68-1) Cap 248,2 pf loaded Q 1.54 Unloaded Q is Zl/ESR = 38,7 / 0,19 = 200.
If I short the measure points the loss is 0.2 db the loss of the series tank is 0.263 db -> ESR of 0,19 Ohm