Hi - A friend send me a 16s Howard to look at with some other P/Ws that needed attention. Thinking it was a Howard from say 1910 or so, said OK. Turned out to be an 1869 E. Howard key wind in a nice silver case! It clearly has a mainspring issue. Whilst capable of doing M/S from 22s down to W/W size - I am reluctant to put a Screwdriver to the plate without knowing what is involved. Would there be a exploded movement diagram I can find? Does someone have experience with this Movement? Appreciate any suggestions....
Thanks from the Aussie.

Front for info:

Not much different to most key wind key set from the back watches Phil, just be careful when refitting center pin arbor that you put the correct tension on it and you do not forget to have the tension/wave washer in place, as it needs the correct end-float.

Also support the arbor when pressing on the canon pinion, do not over tighten it or you can lock the center wheel with to much pressure as it can distort the plates.