I don't usually do anything with the bottom bracket on these because new QUALITY cotters are so expensive... Unless of course it is all 'crunchy'. Otherwise I do the oil down the seat tube trick and put it off as long as possible...
DL-1s are my favorite, I think at last count I have owned something like 15 of them. Most find their way to someone else, but every one gets the treatment wahoonc recommends.