There is a plan in the Archives (I think it's bound with the MIs) that shows the area of the churchyard affected by the widening of St Philip's Rd in 1967. Gravestones were moved to new positions within the churchyard. I had assumed, wrongly it seems, that the human remains were moved with them. Or maybe they were but the remains from unmarked graves were re-buried at Abbey Lane?!
In any case all the remains recovered in 1991, when the graveyard was completely cleared, were also buried in the same section of Abbey Lane - section B (consecrated). this section was used for other re-burials as well such as those from St Paul's.
The Abbey Lane plot numbers quoted form two blocks not far apart. I don't know if they are marked. I walked through this area last year after locating the 1991 plots but I didn't know then that these earlier re-burials were there. The 1991 remains are covered by several gravestones brought from the churchyard. It would be interesting to know if the same method was used in 1967.
I have a photograph of the 1967 plan and also one of the plot plan for Abbey Lane section B if you are interested.