We are replacing a damaged allloy boom (that had a track) with an alloy tube without track. (David, thank you for the specs for that!)
Sail area 416 sq ft there are grommets every 30cm (10mm hole diameter)  The sail is flat, by the way,  we are going to leave it that way to get her up and sailing and I'm going to work on the spare sails, putting camber into them when time allows.  It'll be interesting to compare the two!

I was going to attach an outer boltrope and lash to that, but it would be quicker to use the grommets for lashing. Question is, what do you recommend - continuous lashing with heavier cord or individual lashings at each grommet with same weight (4mm?) as that for battens??  Are individual ones better on the grounds that they are less likely all to fail at the same time?

I have a feeling Arne would recommend attaching an outer boltrope anyway?  What puts me off is that we have bamboo battens which are not uniform in diameter, and splicing the loops in (with tapered splices too!) fills me with dread! Especially as I'd have to do it on deck and it's so cold here at the moment! Is this something I just need to knuckle down and do, to transfer the weight from the sails to the battens?? 
Any advice appreciated!
Lesley