Thanks Godwin,
While I was rebuilding it, might as well retap the hole for a barbed nipple and run a line up high.
Do you have the specs on the barbed nipple? The last time I had a t-case out I was thinking about doing this but never got around to it. On both 60s I've popped off the cap and forced a length of fuel line (1/4" I think) over the remaining vent stub, using a hose clamp to keep it on. The barbed fitting makes for a more secure solution.