NDFS 577 DIES

[Richo]

Can anyone explain the markings of NDFS dies, old or modern as i have around 20 all mixed up in a box,all in very good condition that i am trying to sort out, i dont shoot blackpowder and never have so these dies area bit of a mystery to me.
All seem to be for 577" in one form or another some are marked up and some haven't got anything stamped on them at all.
I am wanting to sort them into sets and finding its not as simple as modern dies, some of the markings are self explanatory but due to the fact i dont have any cases cant be 100% sure what there for,.
Heres a few examples below.
M577"S, O/L, OLNRR, M577"S.590 O/L, MN02M, MN02R 577/450.5T, N/R and Shell holders No19 & 22 some expanders are marked 472 other are unmarked and several die bodies are unmarked, I assume these are for 57u/45₩, Snider and No2 Muskets and O/L is overall lenght!!
Tried seaching on the net but can find anything thats useful for identification, any guidance would be appreciated.

[MrD]

I've got a set of 577/450 dies which I was told were NDFS.
The expander die has no markings anywhere
Seating die is only marked M577/450
F/L sizer is M577/450.5R
Neck Sizer is M577/450.5NR

[Richo]

Ok thanks for the info, i should be able to make up some sets based on those markings, its the .5R that i didnt understand, not that it matters at least i will be confident they are in sets.