I’ve printed using both, ABS and PLA.
PLA prints better.
Also I think that printer has currently 0.3mm nozzle and this should be checked through test print.
When printing using Cura - use the following settings:
Ultimaker Original with Bed Upgrade - SelfBuilt
It would also need to be tested in the full settings -> “Advanced” - Nozzle size - 0.3mm
Use right kind of material.
At the moment it is abs - 240C extruder and 100C - bed.
I would buy more PLA filament as it gives better results guaranteed.
Would repeat it again - PLA filament is easier - if possible get some.