I have an airline approved kennel that I haven't quite got round to selling. I used it to fly my dog from Budapest and it passed all the necessary requirements for flying and is airline approved. I bought detachable wheels for it too so I could haul it around and then just detach them when needed

It has a storage compartment too which was handy for storing the wheels and dog food
It's only been used once (still has the airline stickers on it!) and its wasted here! I think its 92 x 64 x 64 cm (L x W x H) if you would be interested?
I spent almost a year organising bringing my dog from Budapest to Dublin and can tell you anything and everything about travelling with a dog and which companies to use and who to avoid. Flying direct to Dublin was going to cost me 1200 which is outrageous (there is only one vets practice for the entire south of Ireland who can view and approve a pet according to their passport...so they can set their own price!). I instead flew Budapest to Manchester, Manchester to Hollyhead via train (with an overnight stay in a travel lodge) and then used a ferry to Dublin. The entire thing cost me about 600! It took a little longer but it wasnt stressful at all and I would do it again if I had to! Everyone was so helpful especially when they saw I had a dog and had traveled so far!
So yep, if you need any help at all or are interested in the kennel please let me know