New(old) project! Help!!

[pagunslinger]

recently was given a westernfield model m550cd 20 ga. Know nothing about this gun but the action looks like a mossberg 500! need a different barrel and was wondering where to look for it! It has a select-achoke on it now and would like to get a barrel with a screw in!  

[pagunslinger]

From online info i have found that 500 parts will work but would love to have conformation before getting a new barrel! Any1 know where i could get a barrel for it???