Need 2 experimental electronic songs mixed/mastered

Hello. I am currently working on a 4 song electronic/experimental EP. I have already had 2 of the songs mixed and mastered by a brilliant engineer, who basically fell off the face of the planet after he finished those two songs. The two remaining songs need to be mixed and mastered, and one of those songs needs some work on the production. One song has vocals and the other is instrumental though it has samples A thing that is really important to me is the volume of the tracks - they need to match the volume of what the previous engineer did (see attached mp3). The other thing I care about is timeframe - there's no rush here, but I really don't want to wait 6 months while you "work on" my track just to never hear from you again. Thanks.