Section 5520. Omissions; appeal by improper method

(a) Omissions.  If an
  appellant either serves or files a timely notice of appeal or notice  of
  motion  for  permission  to  appeal,  but  neglects  through  mistake or
  excusable neglect to do another required act within  the  time  limited,
  the  court from or to which the appeal is taken or the court of original
  instance may grant an extension of time for curing the omission.
    (b) Appeal by permission instead of as of right. An  appeal  taken  by
  permission  shall not be dismissed upon the ground that the appeal would
  lie as of right and was not taken within the time limited for an  appeal
  as of right, provided the motion for permission was made within the time
  limited for taking the appeal.
    (c) Defects in form. Where a notice of appeal is premature or contains
  an  inaccurate  description  of the judgment or order appealed from, the
  appellate court, in its discretion, when the  interests  of  justice  so
  demand, may treat such a notice as valid.