Luxembourg 1906 Perforations

So I'm still working on my pages...
For the Grand Duke William issues of 1906-1908 Scott says perf 11, 11½x11 and one (37½c) with perf 12½. Michel says perf 11, 11½x11 and that same 37½c with perf 11½x11¼ and 12½. I just went through around 50-60 of these and found absolutely zero perf 11. I did find two examples of the 11½x11¼ plus one of that denomination 11½x11 (and believe me I had to look three times to verify it wasn't the same as the others). With every other set I've looked at so far, when they say there is more than one perf variety I find a few in most of the options. This is the first where they are all one perf type. Usually when Michel says there's more than one type they show differing values if one perf is scarcer than the other. Am I just running into some weird odds, are there really no perf 11s or are the 11s just really hard to find?

Hello,
according to my old Prifix catalog the only value perf. 11 is the 10 c.,it is scarce and comes from the so called first run issued in sheetlets of 10.
Unificato 2003 gives a value of 750 euro for the sheetlet of 10.

Ah, that makes perfect sense then. I'll revamp my pages for the issue to reflect that. I actually just received my copy of the sheetlet this week, but haven't had a chance to test the perfs on it.

So I have examples of all perf varieties now. All values have perf 11½x11, only the 10c has perf 11 and only in the sheetlet, so individual stamps would be really tough to find. The 37½c also comes in two more perf varieties, 11½x11¼ and 12½. I haven't yet found a used example of the latter, but expect they are out there. Note also that the 11½x11¼ and 11½x11 are very close to each other, but can be told apart either by comparing the side perfs on the two or with a decent gauge that handles incremental perfs between the ½ range. Prifix just called the 11½x11¼ one 11½...