Refilling the forks with oil

After reading in some older posts of different ways (some very long and weary) how to change the fork oil, one method caught my eye after realising the previous owner cut M6 threads into the drain holes and introduced very primitivly constructed flathead screws.
To drain the forks I jacked the frame to raise the front wheel and have left them to drain in receptacles for several days.
It is then my intention to the fork oil with the device I constructed below pinching the plastic pipe between refilling the syringe......
I hadn't found a little tap yet but maybe one turns up