The one you have just posted by IXO were made by order of a spanish publisher named Altaya. They sell collections, and the one for the CB750 was named "Motos clásicas de colección". You could buy a 10 page monography and the model for 8.95 euro. It covered the Commando, the Square Four, the Bonneville, some spanish bikes, BMW's, Terrot, Ossa M9ck Andrews, Montesa Sammy Miller etc.
I have the CB750 model, and even sold a couple of them on eBay. They are very detailed, but unfortunately they couldn't match the colour and the model has a hint of orange.
Xtalon, the Minichamps models doesn't come bolted to a base and inside a box. They come in a box with a molded plastic surrounding it. The only way to enjoy it is to get it out of the box and display it. Obviously, if either the seller or the previous owner had it displayed, chances are something got broken. I rather buy one from the shop, picking it up from a pile of unopened boxes, just to make sure the last time the box was open was when somebody at the factory put the model inside.
I would hate paying 80 euros to get a model with a broken brake lever or cable just to read the seller say "I'm sorry, it was perfect when I send it. Must have been a bad handling at the post".
Raul