[xsl] Wrapping two different elements in parent element - part two

[Bruno Nahod <bnahod@xxxxxxx>]

Hello,
As you may have read in my previous post I am working on transforming 
really unbelievably unstructured xml export from a dictionary 
application  into a well formed xml document (based on TEI 
recommendations). Thanx to George & Vladimir I have solved (I mean they 
have solved) my problem. But I have found some exports that have 
slightly different structure but this difference is making things more 
difficult.Also my boss has change the desirable outcome to some extend.
So this is what I have and what I'm hoping to get.


What I have:(Export)

<something>
   <word_case>N</word_case>
   <word_form>some_word_N</word_form>
   <word_case>G</word_case>
   <word_form>some_word_G</word_form>
   <word_case>D</word_case>
   <word_form>some_word_D</word_form>
   <!-- THIS IS THE PROBLEM-->
   <word_number>pl.</word_number>
   <word_case>N</word_case>
   <word_form>some_word_N</word_form>
   <word_case>G</word_case>
   <word_form>some_word_G</word_form>
   <word_case>D</word_case>
   <word_form>some_word_D</word_form>
</something>

What I'm hoping to get:
<something_else>
   <form>
       <case>N</case>
       <orth>some_word_N</orth>
       <number>sg.</number>
   </form>
   <form>
       <case>G</case>
       <orth>some_word_G</orth>
       <number>sg.</number>
   </form>
   <form>
       <case>D</case>
       <orth>some_word_D</orth>
       <number>sg.</number>
   </form>
   <form>
       <case>N</case>
       <orth>some_word_N</orth>
       <number>pl.</number>
   </form>
   <form>
       <case>G</case>
       <orth>some_word_G</orth>
       <number>pl.</number>
   </form>
   <form>
       <case>D</case>
       <orth>some_word_D</orth>
       <number>sg</number>
   </form>

</something_else>

As you can see the transformation should stop at 
"<word_number>pl.</word_number>" and change the "<number>" to pl. or 
different transformation to start at that point?
I would really appreciate if someone could solve this.
Thank you all in advance
Best regards

Best regards
Bruno