O.F Mossburg started in 1919, I knew they had made rimfire rifles since before the 1940's they made bunches of rimfires for the Military's basic trainging marksman programs.
NumrichGun Parts lists parts for 195 diffrent model& submodel varients of rifle mostly rimfire models, they did produce centerfire models.
I'll mention some below
Leveraction model 472PRA&PCA, 479PCA,SCA,PCB,SCB and the 679
Mfg 1972 -1980 all conventional looking tube fed lever rifles resembling Marlins
some with diffrent sights, straight and pistol grip and short mag and long mag
in 30-30Win and .35Rem
(Western Auto, Montgomery Wards and NewHaven)
They came out with 3 diffrent Bolt action bolt head types 2 lug, 3 TRI Lug and 4 (dual) lug
the 800 has a triangular locking lug layout that uses a SAKO type plunger ejecter and extracter claw,
800,A,B,C,CVT,CSM, Western Auto 220A&B, Montgomery Wards 780,767,782,768 and New haven model 900A&B
the Model 810A&B,Western Auto 210A,Montgomery Wards732,734,765,766 and New Haven 910A&B had two parallel rows of locking lugs (4 lugs 2 on each side the bolt head)
The RM7 has the same basic 4 lug bolt of the M810, diffrent trigger/sear/mag
Mossberg model 1500/1700 rifle parts are in the Smith & Wesson model 1500 section are essentually the same as the Weatherby Vanguard, Post 1981 they are currently being imported by Interarms as the Howa High Power Rifle
The link below is a little confuseing they run two columns on the page so watch for the model