Sorry Robin,
Think you are suffering from a senior moment or a surfeit of French wine. Webra are still going strong as far as I know. West engines are in fact highly modified Webras. HP are out of business, well they gave up making model engines, although they still make guns I believe. Mecoa have purchased the rights to the HP engine range. They may in fact still offer spares or even engines, check their web site.
Best regards,
Andrew