A quick response is that "less welding is better", but that doesn't tell you what you need to know.
By the same token, there are a lot of factors that need to be known to answer you question fully and completely.
I will start with a few assumptions that may or may not be correct, thus my answer may not be applicable to your situation.
Assumptions:
Base metal - plain carbon steel
Preheat - none required
PWHT - none
Thickness - 1/2 inch or less
Welding process - SMAW, FCAW, or GMAW
Size of previous weld - 3/8 inch fillet, multiple pass
Given the above conditions, the HAZ is most likely 1/16 to 1/8 inch and no grain coarsening has occurred.
Those being the conditions, you can remove the existing lug and replace it with a like lug without any difficulty.
If the actual conditions are different, you need to provide additional information to get a response that is more appropriate for your specific situation.
Best regards - Al