And what is real slew rate of LM308? I have two datasheets and none of them mention it.

The value in my head is 0.3V/us [Edit: maybe 0.03Vus] maybe for C=100pF?. However it depends on the compensation cap. There a lot of info scattered in the National Semiconductor Linear Applications Handbook. You can derive it from the Large Signal Response graph SR = 2* pi * f_max * Vpk_max /1e6 [V/uS]; use Vpk not Vpk-pk.

One of the reasons for having uncompensated opamps is you can tweak the compensation cap to get more speed. If you have a high gain circuit you don't need such a large compensation cap for stability (against feedback loop oscillation). So that means you can get a higher gain-bandwidth and higher slew-rate. Many designs just use the unity gain value. IIRC, Philips/NXP NE5534 datasheet and associated applications notes had some nice info about that.

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LM108/LM108A Slew-rate calculation from "Large Signal Response" graph

For C = 30pF,

Vpk_max = 14.3Vpk,

f_max = 1.4kHz

SR = 2 * pi * Vpk_max * f_max / 1e3 = 2 * pi * 14.3 * 1.4e3 / 1e6 = 0.13 V /uS

For C = 100pF estimate SR = (30p/100p) * SR(30pF) = (30/100) * 0.13 = 0.038 V/uS