JOLANA STAR BASSO IX was produced by factory in KRNOV since 1970. Basso IX was a very bad balanced instrument, with a very light body.

Here's a couple of words from LordBizarre, the owner of the black bass (pictures below):

The bass came with original leaflet, dated 24 zari 1976, made in Krnov, s.n. 5021; bag and even Checho "Delicia"strings. Please pay attention to the very low quality as can be seen on the neck's back!!!
The bass has a very lightweight body (must be poplar or so... but I'm not a carpenter... so I don't know).
There are two selector switches: one for one-two or both pu's; the other one is sort off 3-way tone control, and there's a master volume knob. Since there's no clearness about serial numbers (this bass carries the sn.5021) I presume that only this can be a "real" serial. With other brands sometimes model number and date are fixed into the s.n.

Jolana Star IX guitar - a close relative of the Basso IX

Credits:
Jira Jaromir (Czech),
Jaroslav Hol?sek - Czech Republic
Andrij Karpenko,
Big Beat - JunkGuitars.com
Lordbizarre - LordBizarre.com