Among eyepieces of the past, the Clave and Brandon eyepieces seem to stand out in most of the reviews. Even today after Clave has been out of production for many years they still sell for unbelievable prices, if anyone chooses to part with them. Even the old catalogs seem to be collector's items. Clave was sold in the US by Cross Optics out of California(their 1978 catalog) and Roger W. Tuthill out of New Jersey (His 1977 User Report Z-1000). Today the Clave company name still goes on in France. The site (in French) lists several Maksutovs but makes no mention of the eyepieces or what brand they are including with their Maks. Brandons were the choice for Questar to include with their Maks. They are still sold today at a reasonable price by Vernonscope.
The current top of the line are Nagler Ethos, wonderful field of view and specs but costing as much as most backyard astronomers paid for their complete telescope. On the other end of the price scale you read that new eyepieces from Taiwan (GSO) are ranking near the top in quality now.
One of the best article on the history of eyepieces that I have found is "Evolution of the Astronomical Eyepiece" by Chris Lord. It can be found on the Braye Brook Observatory Site.
I have scanned an item or two from the 70's for the blog.
Clear Sky - Rich