Hi, sorry for the delay in getting back to you!
Sorry to hear about your device failure and data loss! No fun.
To answer your questions- start with whatever fuel up you have available. If it's from last week, or last month, just enter the log. I realize your concern is regarding the lack of data (gap) between April and July. So with your first entry (let's presume July 1st), ensure you've checked "Missed Fill-Ups" in the New Record form.
This lets the app know that there may be data missing prior to this record, and to start calculations again from this point going forward.
Cheers!
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