About 2.5 months ago I was the victim of burglary and managed to shoot the intruder while he was fighting with one of my roommates. The police confiscated my pistol and did not give me a property receipt for the gun (although they recorded all of the recovered property on a property receipt).

I am not being charged with anything, but have been subpoenaed a couple times as a witness along with both of my roommates. I wrote a letter to the PPD and was told to call the Gun Permits Unit. After giving the property receipt numbers for the recovered property (but not the pistol as they never gave me a receipt for that) I was told I would receive written notice in the mail. I called after waiting 6 weeks, just wondering if I could get an update and the officer was very rude. The next day I received a letter stating, "The Philadelphia Police Department does not find it feasible to comply with your request". It mentioned I could file a petition under rule 588.

Questions:
1) Do I need an attorney to file that petition, if not, would having one help?
2) How does one go about filing such a petition? Is there a form I can print out online or do I need to go to a courthouse and get one?
3) What are the chances of me getting my gun back?
4) If hiring an attorney is necessary or would greatly increase my chances of getting my gun back, does anyone have any recommendations?
5) What constitutes proof of ownership? I have a receipt from the FFL and a carbon copy of the PSP Application/Record of sale, will that be enough?