There have been many variations in the MacLaren tartan swatches used on the traditional Wood Badge neckerchief. David Miura has graciously supply scans of variations he has in his collection with the following notes:

Three are from the UK (most likely Scotland) and the other two are from the US. I noticed that the BSA versions have vertical woven horizontal strips whereas the UK versions are always horizontal. You'll also notice striking differences in the color of the neckerchief itself. I'm guessing that this characteristic, along with the type of McLaren swatch, would help to date each n/c.

The one I've labelled UK-1960 is confirmed from the early 60's. I met a woman whose father received the Wood Badge in 1962 in the US, and know of another person who received their Wood Badge in Finland in 1963. They both have this type of n/c. The UK-1994 is a wool n/c that I received as a gift in 1994.

The US-1989 is my own n/c that I got back then. The other one I don't know when it's dated, but it has an unusually bright green swatch and an unusually red n/c material. Perhaps over time, people will start to place dates around when these varieties were issued.