Thanks for that Ian, it is an inexact science at best to even attempt to guess which Meconopsis will or indeed can even hybridise with each other. Saying that I would say that you need to adjust your entry for napaulensis. Many years ago I can remember having a nice napaulensis type Meconopsis in full flower and wondering (as you do, well I do anyway!) whether it could possibly be crossed onto any of my perennial blue flowered Meconopsis to maybe get something napaulensis like but maybe with a lot of luck perennial. I tried quite a few different combinations backwards and forwards using the napaulensis plant both as seed and pollen parent onto various perennial blue Meconopsis which were in flower at the same time.
Out of all the crosses that I made just one of them actually produced viable seed, which was I think using napaulensis as the seed parent. Of course being me and given that it was a long time ago I can't remember which perennial blue Meconopsis provided the pollen! I did take a lot of photographs of the hybrid seedlings as they flowered in their second year and most impressive they were too, a surefire award winner in all the important details, strong flowering stems with vivid blue flowers all the way up them, larger than napaulensis flowers but reminiscent of them, height was kind of similar to Lingholm, except for me the most important detail. They were all monocarpic, loads of big fat seeds produced which proved to be infertile in the end.
I will have the transparencies of these hybrids tucked away somewhere in a box and I think that I probably marked the other parent onto the slide mounts in marker pen. So, it is unlikely but given a bit of encouragement napaulensis can hybridise with more plants than you originally might have thought.
Maybe worth someone trying a few more experiments with napaulensis again to see what is possible but you'd be very lucky to get anything perennial out of it and to me that is kind of an important quality in a garden hybrid. I did try to cross the hybrid seedlings with various other Meconopsis but nothing worked at all, probably too complex a hybrid, maybe some of my newer hybrids might have been compatible but given the mixture the chromosomes could have been diploid or tetraploid even. Possibly a complete fluke that it worked at all, which maybe makes the point, never assume that something won't be compatible if you're thinking of hybridising. If there is even the vaguest chance that two plants might be able to hybridise, it costs nothing to make the attempt, you have nothing to lose and everything to gain.
I know that Ian is trying to keep the monocarpic Meconopsis pure bred as it were and this is a worthy aim and it is in all our interests to keep a supply of fresh seed available for these plants.