Just a wee correction, Allan - Aurora didn't make the Avro 504. Back in the 50s when Aurora made their original batch of six WWI "1/4 scale" kits, a company called J&L Randall in the UK decided to copy the models and release them under their own 'Merit' label.
They were exact clones but with different sprue layout and without the great bases and ground crew. The models were the SE5a, Camel, Bebe, Albatros, Fokker Dr.I and D.VII. I don't know why they didn't clone the later Aurora Pfalz, SPAD, Tripehound, Eindecker, D.VIII or Nie28 but they didn't. Maybe legal action?
Instead they released a few of their own designs - The Avro 504K, and DH2, as well as, OT, a Walrus, a Swordfish, a Bulldog etc.
When Aurora went west, their moulds were acquired by Monogram, then Revell, although some were famously damaged and lost in transit in a train wreck.
However the Merit moulds were seperately acquired by an Italian company, Artiplast, who added an Ansaldo SVA5 WWI design of their own. When Artiplast went bust, these moulds were acquired by the Czech Smer company. (Also acquiring a 1/40 SPAD from Heller.)
Sorry to be long-winded but I find this history quite fascinating. Maybe you will too!
The Merit-Smer Avro is a pretty ancient overscale chunky kit, which I built decades ago, and is without doubt inferior to the much more modern and accurate Blue Max kit, although that one is moulded in the typical buttery plastic that Chris Gannon favoured (and some don't like!) I'd definitely go for the BM kit.
However if you are looking for a contemporary old-school build to match your Albatros, Bebe and D.VIII beauties, maybe you would prefer the antique Merit-Smer offering?
Sandy