Yes, now romans for Part work from the version in git.

I only got messages from run-tests about not finding the files:
parts/index-1-6-part-good-Part--1.html
parts/index-1-6-part-good-Part-1.html
parts/index-1-6-part-good-Part-2.html
parts/index-1-6-part-good-Part-3.html

Reopened the bug. I take it that Book numbers are also roman numerals? I will continue as if it were so; I was not able to find a current documentclass which carries it.

Committed. All we need now is some help from the translators (I was looking into [http://translationproject.org/ the Translation Project to ease collaboration).

It should be solved now, please confirm with the enclosed version. New code has been added to deal with appendices, and a new translated string.

(file #21694)

Yes, now numbering is correct with appendix in child, but the label before the numbering used in table of contents, or in links with "--splitparts", remains the same for appendixes as for the normal section in article and chapter for books (first level) instead of "Appendix" (or the corresponding translation). The second level (subsection in article or section in book) could use the same name as the ones outside appendix.
Thanks.

With eLyXer 1.0.3, if the first section/chapter in the appendix is inside a child document, then the numbering of sections/chapters in appendix does not change to letters. It continues with numbers, even for other sections/chapters in appendix directly in the master document after the child document.

If the first section/chapter in the appendix is directly in master document all goes OK and the numbering in the appendix is done with letters, even for sections inside a child document after the first one in master.

Please, find attached a test document and his child document to show the problem.