I used them on my 1895 and I know they fit the front two holes on the 1894. I think they will also fit the rear two holes they only hang of the rear of the reciever because the rear two holes are not as close to the end of the reciever. I used a full length pitcanny rail on the 1895 at first but the sight just looked kind of stupid sitting there on the rail, and its a lot hight than it needs to be. The burris mount is really thin and keeps the sight like a 1/4" lower.
I know the mount will work on the fron two holes because my buddy did it, I also know that some have redrilled the mount of the reciever to move the sight forward so it does not hang off the rear. I have seen them with the sight mounted and hanging off the rear. yOu can buy anybodys pitcanny and use the burris pitcanny mount and it will work it will just not be the nice clean installation the the burris mount gives you.
When I bough my 1894 I put a tang site on it, but the first time they are a problem one of these fast fires is going on it. They are reall y fast to shoot. And do not look as bad as a regular scope. In fact they kind od look like an after market peep, and the nice thing is that if the batteries die you can use you factory sights.
I attached a picture of the burris mount on my 45-70 so you can compare it to the pitcanny set up.