These bogies are light years ahead of previous efforts to produce an Irish B4. They are the correct overall width and have room to convert to 21mm gauge. They even have built-in pickups for lighting.
Interesting use of 1mm pinpoint split axle stubs - these won't be easily compatible with P4 profile wheels (which are usually 2mm bore), so perhaps some sort of adapter/converter axles are required.
Will be useful as upgraded bogies for Murphy Models Cravens and Mk2s but bear in mind that the mounting methods are completely different, so improvisation is a must. Comparison photos included in this review.