Clerks of judicial courts, judges and registers of the probate courts, judges and clerks of the District Court shall not sell or deliver any blank writs or precepts bearing the seal of said courts and the signature of said judges and registers to any person, except one who has been admitted as an attorney in accordance with the laws of this State. Said judges and registers of said probate courts shall not receive any paper, petition or other instrument pertaining to the practice of law before said probate courts unless it bears the indorsement of an attorney or counselor at law duly authorized to practice before said courts. The above provisions shall not apply to a party in interest in the subject matter in said courts.   [PL 1979, c. 663, §77 (AMD).]