audio engineer required

Requiring a experienced audio engineer to clean and/or remove as much as possible a vocal delay from a conversation for transcription. The conversation and transcription are to be utilized for legal and academic purposes (original and cleaned). The audio files develop a predictable delayed echo starting off small then over time a second or more vocal delay out of sync with the lip motion, (samples from beginning and end of conversations attached). Audio quality needs to be clear and concise to forensic standards if possible or as much as possible to remove the predictable delayed echo and periodic pops and crackles. all audio files and duration's, audio 1/ duration: 39 minutes, 3 seconds audio 2/ duration: 39 minutes, 13 seconds audio 3/ duration: 4 hours, 10 minutes, 16 seconds audio 4/ duration: 2 hours, 9 minutes, 32 seconds audio 5/ duration: 1 hour, 37 minutes, 59 seconds audio 6/ duration: 1 hour, 54 minutes, 2 seconds audio 7/ duration: 51 minutes, 8 seconds If this is the kind of work your capable of doing or have done so before I look forward to working with you, thank you.