It’s celebrated in the first clue. Some unfamiliar words made it a little harder than sometimes for me. Congrats to Quixote on reaching this landmark. If an anorak wishes to probe why the paper itself is numbered 898, good luck to him/her.
Solving time: 30 mins
* = anagram
ACROSS
6 ACME “High point, a No 900 – Quixote’s latest” A CM (900 in Roman numerals) last letter of Quixote.
7 L (IME S)TREET semi reversed in (letter)*
10 MON T(R)EAL Mon = Monday i.e. tomorrow (on Sunday)
14 DEALER Refers to cards – four suits
12 Christian DIOR Fashion designer – hidden with misleading context.
16 CIDER Hidden reversal
19 SENE SCH A L Historical steward (seen)*
DOWN
1 S COOT ING grass = inform
2 SE TT ER Amusing surface
3 BLUEGRASS STATE (USA settler bags)* Kentucky
5 CEREUS “Serious” US prickly plant – new to me.
18 NINE PINS Good surface Snip reversed
18 CHUKKA From polo “Chucker” (from cricket)
20 CU’S HAT New to me – a pigeon, mainly found in Scotland Cu = symbol for copper