Base & side edge angle?

[Jacques]

This is what I meant by “flat bastard file on a 45 degree angle”. Use light pressure and the 45 degree angle to prevent the file from flexing and lightly drag the file tip to tail to check for any edge high spots. If any high spots are found, work the area in one direction while lifting the file between passes and cleaning the file often.

View attachment 114585

Yea, I figured this is what you meant. The old flat filing method. Very good to have a smooth interface and not a high steel edge where it meets the plastic.
Thanks for taking the time to clarify for everyone.