Printer Jam - Restarting Print?

[Tetraodon]

I just checked up on a print today to find out the filament jammed about 1cm from completion (my first ABS jam with this filament - it's been going so well!) - obviously there's the choice to acetone it, but I was wondering whether I could try to print on top of it. I'm not sure whether the ABS will bond with cooled filament, which is obviously an issue. But I'm wondering what's the best way to go about it?

Would it be better to:

1. Start the bed at the height of the jam (and hope for the best) by changing the Z-axis offset?
2. Start the process at the height of the jam (and also hope for the best)?

The first option involves me having to move the object in the software to below the build plate, which creates a second chance of producing errors, and it'll also start like any first layer with a solid bottom layer. The second, however, I assume means the bed is going to level at the original offset, which will crash into the already printed parts.

I can see two major issues:

- The Makerbot starts with the extruder at the front right hand corner of the printer - which would knock off all the prints. This appears to be as simple as changing the G-Code to set the extruder to sit on the other side of the printer?
- The primer either attempts to prime at the Z-axis offset on the first option (creating a blob of filament), or attempts to prime at the bed level (original offset) for the second option, which obviously creates another issue where it crashes into the original print.

Before I go ahead, can anyone see any other issues that I might need to counter? (obviously as I can only do this once for this particular print, I need to get it right the first time)

I've honestly not had to touch the G-Code until now, so I'm completely ignorant on it - it looks relatively self explanatory, but any help is appreciated.

[CompoundCarl]

I usually just remove the partially printed piece and then print only the remaining section on the bed. Then I glue them together afterwards.

All the heating and cooling of the parts usually causes issues if you try to leave it on the bed the whole time, so this works better for me.

[Tetraodon]

I accidentally left the dial caliper at home, so have no way of accurately measuring where it messed up, so will have to acetone two different parts - such a shame when most of it printed successfully