How to add LAME Metadata about precise track length for gapless playing to --nogap encoded files (with this option LAME metadata isn't stred into file), which playing isn't gapless.

I've marged mp3s with mp3marger to obtain .cue, then splitted marged mp3 with pcutmp3 using that cue. Finally I've got true gapless mp3 playing BUT track position in album is SHIFTED twice:
1) when encoding with --nogap
2) when splittion by pmp3cut

I need tool which simply adds LAME metadata to lame-encodet files without metadata.