...not just classic, but specialized classic material, which is very hard to find on open market. Than come next one point, it is in mint, never hinged condition, that is valued in catalog almost twice the catalog price.
Here are Michel numbers, which, if You will check in Your collection, is probably missing:
A 19/20 I, 30/32, 139/44, 164 A+B, 320 C, 348/49 F, 348 E, 356 B, 430 A, 439/40 A and great 439 I (with engraver "S" mark).
Go after it, as catalog prices are constantly going up for this kind of material, and scarcity on open market are very visible, even on eBay You will not find it!