You did not state where the Luger is now located. If it is in Mass the following would apply:
IF the person who has the Luger now has a valid FIC (firearms Identification Card) leave it with that person until you obtain an FIC from your local police agency. In Mass the permit issuing authority is your local police agency. Contact them for detailed information on obtaining the FIC. After you obtain the FIC you may lawfully take possession of the Luger and register it using Mass Form A-10 which you may obtain on line. The transferor will be the executor of the estate of the decedent.
http://www.mass.gov/Eeops/docs/chsb/firearms/FA10.pdf
If the person who now has the Luger does not have an FIC, it may be brought for safe-keeping to a person who has a valid FIC until you obtain yours. You would then register the luger using the above referenced form.
I researched the law for you this morning but the procedure for accomplishing this transfer is really not spelled out in the applicable statutes so the above information was obtained by me in a telephone conversation this morning @ 0920 with the Detective in charge of firearms licensing in the Medford Mass. Police Department, (Det. Mulcahy 781-391-6769). The Detective was quite cordial and glad to offer his help in answering my questions.
Because the FIC is issued by the local police agency my advice to you is to contact your local police agency and confirm that the procedure will be the same in your jurisdiction.
If the Luger is not in the State of Mass. you would need to:
1. Obtain your FIC
2. Have the gun brought to a FFL (Federal Firearms Licensee) in the state where the Luger is now located.
3. Have the gun sent by that FFL to an FFL in your locality.
4. Have the FFL in your locality transfer the firearm to you.
If you have to go this route you will need to find an FFL in your locality to take delivery of the luger for you. It is common for them to do that although there is generally a charge for the service. In my part of the world it varies quite a bit- from $20-80 dollars. Of course the person who has the gun now would have to do the same thing.
Bottom line: You may not possess the firearm in Mass. until you have obtained your FIC, but the law will permit you to do so if you are qualified to obtain an FIC.
Regards,
Doug