I found the Deprotector for VB AntiDecompiler tricks, but my two version of DoDi's decompiler can't decompile itself with diagnostics "Error in Discompiler logic!"
and the resulting source is not compilable. I don't know, if there is exists newer version of this programm (my most newer version is 4 Jan. 1996). But in any case i can reconstruct the decompilation algorithm and VB opcode from given source.
But, now i see, that this way is very long. Now i try go in alternative way.
I will intercept the USB traffic to the hardware via USBmonitor. and i hope, that this information will be enough for reconstructing of hardware interface