Jolana Disko bass is a copy of Gibson RD Artist bass. With a couple of minor differencies, of course...
The body is made of some wood I could not identify, but it is very light, probably poplar or fir. Neck is also made of some bright wood (fir?), with rosewood (it's a bit lighter than usual rosewood, I've heard it's painted beech) fingerboard. Headstock have a different shape from the Gibson's, it is something in Telecaster style - they were probably recycling Iris bass necks. On my bass there was no headstock logo, so I've made one in Fender style. On the right there are pictures of another stock bass and it does have a logo. Tuners are Jolana's, and they are really cheesy. Body, with its distinctive "RD" shape, is very comfortable - both when played seated or jumping around. Adjustable bridge is very similar to Jazz, but with bigger saddles. This bridge tends to break strings. I don't know what is exact reason for that, but strings on this bass break very often. Two soapbar pickups deliver the crappiest bass sound around, all the circuitry is passive. Bass pickup is a bit louder and much meatier than the bridge one which is really useless, with no bass frequencies at all. There are volume controls for each pickup, and if you roll off the bridge pickup completely it suddenly boosts the output level. In addition to all this pickups happened to fall slightly off the strings' axes which results in lower E-string's volume. Even if you pick it much harder, A-string always sounds fatter than E-string. The best solution to this was to use it as a 3-string bass (balalaika). I'm not sure if it's a common disease among Disco basses or is it just my specific bass.
Inside the bass there's no shielding or conductive paint, just clean wooden surfaces.
Truss rod on Jolana Disko is accessible from the headstock's side. I tried to rotate it but it does not affects the neck's curve.

Okay. What this bass is good for? It looks very cool and it's light. I think it's good for shooting videos. Or shows when you use playback. It's also nice for breaking onstage. That's about it.

Specifications:
made in Czechoslovakia
body : Gibson "RD Artist" shape, unknown light wood (poplar?), four pieces glued together
neck: bolt-on, rosewood fingerboard, rectangular inlay, 21 very small frets with flat crowns, zero fret, tele-style headstock with no logo
The rectangular neck plate shows "Jolana" logo. The neck is screwed to the body with 4 big bolts, and there's another, thinner bolt in the middle of the neck plate also holding the strap knob.
Nut:Black plastic, very deep slots (about 1.5 string diameter)
pickups: two passive Jolana's with black plastic covers, with an image of "humbucker" - it's divided in the middle and shows two oval shapes (see closeups). From the rear side pickups are filled with some sort of paraphine, so noone can see their real structure. I'm not sure these are humbuckers because they produce strong hum when soloed.
hardware: chrome
controls: two volumes - for each pickup. Control knobs are Gibson transparent white design, but on this bass they broke and you can see black jazz-fender-style knobs.
There's a serial number on rear side of the neck, close to the joint, and on this bass it is 0777. Does anybody knows how to decode it? It is not 1977, because the bass must be younger.