No worries. Those mid-2000s PSII builder kits have a sort of cult following. They really weren’t very popular when Estes first released them - except maybe the Mega Der Red Max - but when Estes then parent company Hobbico started struggling financially they discounted them deeply and folks started buying them up and modding them. Now with most of the proprietary tubes and nose cones unavailable even the repros are getting scarce. But there’s plenty of MPR and low-end HPR kits out there from other sources so no shortage of rockets in that size range - just none with the Estes brand.
It was an interesting experiment for Estes. They bought the composite PSII labeled motors from Aerotech - no idea if the plan was to eventually make their own APC motors for sale to the hobby community, others might have some insight into that. The kits couldn’t have been cheap for Estes to make and had a high MSRP plus they used unique parts not shared with their regular lines. As I said earlier, you can get plenty of like kits from vendors like LOC, Madcow, BMS, North Coast, etc so their demise didn’t really leave a hole in the market. The exception is the MDRM - with that unique nose cone, huge decal set and obvious nostalgia appeal it is missed, kick myself for not buying a couple of those at $50-ish bucks a pop!