Interesting new article about Su-27 and J-11 history (unfortunately in mandarin, I used a translator to read it).
a few interesting points from the article if I understand it correctly:
1. PLAAF actually bought 78 original Su-27 from Russia (36 Su-27SK + 42 Su-27UBK). Then, they license it as J-11 (105 airframes bought as kits and assembled in China). After that 105 licensed airframe, PLAAF decided to switch to J-11B from Shenyang.
2. The article claims that to compensate the Russians for the switch (no words about the original contract, but I believe our consensus is ~200 licensed airframe were planned but only ~100 made), China bought 76 Su-30MKK for PLAAF and 24 Su-30MK2 for PLAN (100 airframes).
Tl;dr: PLAAF might have 78 more Su-27 than I thought (although only in the old original form), then interesting new info about the renegotiation of the Su-27 license (China bought Su-30 to compensate Russia for the breach of license contract).