You've got me confused now Danny. The Parallelweg (to the railway?) seems to be to the NW of Akerstraat and south of the railway (or tram?) so I can't see how that would be a way home from GK. If you exited GK on the Bruunsem side, the present road system would seem to favour the Heerenweg to get home. From the Teveren side maybe the L42/ Heerlenerstrasse?
Similarly, the Akerstraat seems to run NW/SE, so were you at the East end of it, and on the South side? There are two schools showing on the map today (they show up as you zoom in), the Grotius College and the Bernardinuscollege, both on the north side of the road, the former being at its East end, the latter midway. Does any of that help?
Not surprised though if it doesn't. I grew up in Bournemouth, cycling all over it as a kid. I get lost now every time I try to drive around it, with so many new road systems and so much rebuilding. Akerstraat looks like its been "doubled" in its time for a start.