Removing Blueing from Straw parts

[Saturn6]

Hello: I have owned a Mauser Comm. S/42 "G" date
for 5 years. I have fired it at least once a year,
since it is "non-matching" A former owner had all
the Straw parts Blued, is there any chemical that
will remove the Blueing without damaging the remaning Straw finish? Yes, I plan on dismantling
the Gun first. Thanks in advance.

Reguards...Saturn6 (John)