Gun shops, e-gunparts.com, gun shows, want ads, etc..
www.gunsamerica should be able to help
the model 42 is the same as the marlin model 80
The Marlin 780 dosent use a clip, it uses a magazine. You can get these from aimsurplus.com
type in marlin model 80 on google..its the same clip
The Marlin Model 795 rifle does not utilize clips, but has a 10-round detachable box magazine. The rifle itself has a magazine disconnect, and thus will not fire unless a magazine is inserted.
Try Numrich Gun Parts Corp.
Factory magazine for Marlin 80 DL $18 + $7 shipping at ammoclip.com
Magazines are available from Numrich gun parts for around $20 PLUS SHIPPING.
Numrich Gun Parts Corp.should be able to supply you with the magazine in question.
NUMRICH CORP. APROX. $15 EACH FOR A 10 SHOT CLIP NEW, If you need one get 2 just in case !!
Your rifle is a Marlin Model 70. Most gun shops can get a magazine for you- the same magazine is used for several Marlin 22s. You can also order one for $18.60 plus shipping from the website for gunpartscorp. It is Product No. 438340A.
best bet for older gun parts is gunbroker.com they sell most everything gun related