Out of curiosity, before the 1400 series was introduced in 1974, would I be correct in thinking that the 200 series was sold alongside the more deluxe 2000 series?
I don't think so, Nick. I think the 200 series ended in 1968 with the Model 271-B. It seems that Eureka changed to the 4-digit model number format in 1969 with the 2000 series. According to Brian (eurekaprince) the tens' digit reflected the trim level from high to low - for example, 2082 was equipped with more features than 2042.