Well, I’ve got both! Hopefully they’re alive and doing well, one is just a graft on our formerly fruitless Clapp’s Best, but onece I pruned it way back and grafted to it, it started fruiting again. I’m glad I cut out the center and left the main scaffold branches, it was a two year prune job to not shock it too badly since I cut 50% of the canopy off, and grafted on the stub that was formerly shading our most productive apple tree.
And the other is a whole tree growing as a sort of wind break by the road.
Bollwiller/Baby Shipova seems to have fairly broad graft compatibility, at least so far. I have grafts growing well on apple, pear, aronia, and mountain ash, though I have no idea about the long-term compatibility.
I bought a so called “Baby Shipova” this year. It arrived as a tiny little graft, so I’ve fertilized it heavily to push growth. Although it is remaining healthy, it refuses to push any additional new growth above the graft and is only using the fertilizer to stimulate new growth from below the graft (which I have been removing). It looks like it may be hard wired to only put out one flush of growth per year and then those buds stay DOOOOORMANT till the next year.
I grafted Baby Shipova onto Quince last year and it’s doing the same thing. I tipped it a few weeks ago and it’s grown about an inch from the top now. Hoping for some actual laterals next year. It’s in my Fireblight Alley with a quince and two medlars. The quince is similarly fussy and mostly only grew about a foot on the top, though put on more growth this year (quince on quince isn’t dwarfing) overall. The medlars’s laterals grew a bit. They were all transplanted in the Spring, so they’re presumably getting their roots more established.
The one that some unknown person, definitely with dashing good looks and excellent taste (ladies), grafted onto a Bradford pear (with a 1 foot diameter trunk) at the local park grew quite a bit initially and has stalled out since, too. Whoever did that hasn’t pruned the graft or otherwise messed with it this year, just checked in on it a couple times.
edit: I should mention that it did get sprayed with Immunox, but hasn’t had the powdery mildew or rust problems it had last year. So that’s been good too, at least.