TubeNet

I agree with Phil.

Either hire an pianist to play it with you or pick up a recording of it.

'Tis a romantic-esque piece and therefore relies a lot on the piano part to fill in holes and help with harmonic structure changes.

It would be like listening to a Brahms Lieder without the piano part. Interesting, but nowhere near as good.

Sorry, this is going to take a bit of space.

I rather think you might want to figure this piece out on your own, with the help of your teacher and minidisc.
The Lebedjev concerto is a rewarding piece that shouldn´t be overly hard to grasp. Take some time singing it and your personal phrasing will jump right at you. (Actually it made my top three bathtub favourites, you know, the place where everybody turns into the three tenors, all of them)
This is quite romantic, so you might want to try out substantial dynamic and tempo alterations to add dramatics / passion as well as real quiet moments. Especially this applies to the cadenza starting with that three octave passage and (to my opinion) ending with that real fast line going upwards in an accelerando several measures later.
Just fool around a bit and look what´ll work. Exaggerate when practising, only 2/3rds of what you think you play will come across to a listener.
See if you can find phrases that are not too obvious (not necessarily from lowest note to lowest note in any given two measures). Those phrases could take forever, so use cubic miles of air. I´d wait playing with accompaniment until I could make this sound good as a “tuba onlyâ€