Ive been researching SugarCane's M-Series on and off for years..it's 99% complete but still a bit of a work in progress.. First up are the 'MP' codes, from what i can gather they originated around the late 80's, there used to be some bits of helpful info on 90's era Japanese blog sites, Geocities and such, sadly nowadays its all been lost or archived... MP-597 XX replica, redline denim, offset loop, what look like a boxy 50,s cut. MP-603 Circa 90/91, white/silver line, off set loop but look more like a '47' cut MP-604 101Z 'Cane's' Riders released from around 1990/91 MP-619 Lee 101, Pinkline, 'Union Made Cane's' button
None of the MP models have a patch. Production of the MP codes ends before 1992.
I have seen an article in 'Made in Japan' magazine referring to the 1991 release of the M41001 but that was retrospective having been published in 1998, there must have been a few years crossover period.

Next up the early 90,s product codes
M41072 1922-1936 replica M41028 Late 1800's Repro, No back yoke M41030
Late 30,s 501XX using a 13oz white line denim   These came into production in the early 90,s and gained a cloth patch around 1997, There is also a M41030 with standard 'Toyo&CoSPL' fly     M41001 Early 90's Laurel leaf model, late 40,s silhouette, 50,s details, pink-line denim   M41001
1997 cloth patch model, both of these pairs are a 50's repro/details but their silhouette is more 47-esque, most unlike the wide/boxy, exaggerated SC-55's   M41027
40,s Repro 101-B 14oz denim M41057   WWII 101-B     M41051   1936 101 Cowboy Hair on Hide   M41101 Mid 30,s 101 Cowboy M41058 11MW M41059 1947 11MW For comparison here's a deadstock pair belonging to Mr. Takahashi of Junky who also reproduced this pair. Another comparison of the pinkline denim types through the generations Worth noting that the M41001 & M41030 are 1" undersized comparred to the SC-47's and shrink 'from tagged' M41001 Tagged 32 SC-1947 Tagged 32
Other notable mentions

M40333
Bell Bottoms M41151 Painter Pants M41117/M41099 Lot 117 + Lot 99 Ranch Pants, 10oz, buckle back, wide leg
M41102
Lot 102 Engineer Pants, 10oz buckle back, wide leg
M41104
Lot 104 Tool Pocket, 10oz wide leg
M41106 Lot 106 Union Made Logger Pants, 10oz wide leg M41025 Beams x Oriental Enterprises XX. M41001-esque, 'Beams' tab & buttons, no arcs, no patch.   Next up are the 91-97 M-Series Denim Jackets

M11026
WWII 13oz denim (M11317 506XX Cloth Patch  +pocket flap +donut buttons)
M11001 Type2 without patch/outer stitch M11027 with patch M11028 Type 3 All of the above lots started life circa early 90,s and gained a cloth patch before the end of production in 1997 M11317
213 blouse M11002 (M11327 Blanket Lined)
101-J M11141
11MJ M11142
11MJZ Scovill zipper   I hope this helps with the search... If you need anymore info, let me know and i'll see what i can dig up.