I think that no. 6 is probably a Far East copy of a Matchbox 9a/b, but I would like to emphasise that is only a guess and I cannot offer any possible company names. (One for you, Ghosty?)
If No. 6 has JAPAN on the side, it could be a late issue of a model marketed by 'AHI' (Azrak Hamway International), a large American toy distributor and marketing company who struck deals with many toy companies to supply toys for their product line and the small Ahi models were very popular in many countries, being sold as single models or in gift sets.
I does not look like the 'AHI' model I know of, so may be a copy of it...!
I have borrowed for illustratative purposes only, Two pictures from Gary's cars website and overlaid the mystery Fire Escape model and there is no doubt about there being Three different models in the picture.
Just left click on the image to see it fully.
Three 'Fire Escape' models.jpg (136.91 KiB) Viewed 1715 times