Since Mallan's "Amateur Astronomy Handbook" from 1960 featured the Jaegers 5" F/5 build, a lot of info is available on that. Nothing specific that I know of on the 6" F/5, but the 5" stuff can be scaled up.
Surplus Shed STILL has reprints of the Jaegers Cat. No. 3094 booklet "How to build an astronomical refractor telescope. It is Surplus Shed item M4114 and costs $0.95. It contains some photos reprinted with permission from Mallan's book and layout diagrams for the Jaegers 4 1/8" f/15, 6" f/10, and 6" f/15 and a couple smaller refractors. Those diagrams may be of limited use now, however, since the glare stops are dimensioned for a 1.25" focuser and eyepieces.
I just checked and the 6" f/5 Jaegers objective was not available in the Jaegers 1970-4 catalog, but was in the 1973-3 catalog. I don't have any 1971 or 1972 Jaegers catalogs. So that objective wasn't even available at the time when Mallan's book was published in 1960. -Bill