Russell, are you one of the tight 203 owners? If not, would you be prepared to pay around $30 for a shiny new hose to replace the elderly one on your car in anticipation of its demise?Not a problem I've faced with an early car but I've always noticed the poor condition of this hose. Note the experience of Gordon Miller in importing parts and having parts made for sale. He was not happy with the experience and commented 203 owners were very tight and would not readily buy. This is a major outlay and cost it out fully. It would set you up as sole worldwide supplier of the hose but how much demand would there be given it was only used in the colonies and Australia. You need a firm idea of the number of people who will commit to a purchase.
Certainly looks like that!This is how this was solved on my 203, probably was done by either Gordon Miller or Ivan Washington. The hose on the filter is the 403 hose, then a bit of pipe and some radiator hose correct size with a small bend to the carb.
It may be as close as one can practically get. How many bathrooms could you then repair for the cost of 203 hose manufacture?Certainly looks like that!