Most of my rifles are either a Ruger No. 1 or an 1885. Both types of rifles can be a challenge to mount scopes on. Especially for someone like me who wears glasses & seems to need a bit more eye relief than most hunters. The only extension rings that I have seen have been 1" so as many new scopes are only available in 30mm, that can add to the problem. My solutions might not be to everyone's liking but they worked for me. In some cases I simply used a scope without a bell for its forward objective (i.e. a 20~24mm scope) which gave me more leeway to move the scope rearward. This included a Redfield 2.75x, Leupold Big Bore (3x20mm from their custom shop), Meopta R2 1-6x24 RD and a Schmidt & Bender 1.1-4x24 Zenith. Another option was to buy a more expensive scope that had large eye relief & a forgiving eye box like the Schmidt & Bender 1.5-8x42 Stratos, Schmidt & Bender 3-12x42 Klassik, Swarovski z6 1.7-10x42 or the Swarovski z5 2.4-12x50. There were a few less expensive scopes that worked for me as well like the Leupold 6x42, Zeiss 6x42 & Redfield Revolution 2-7x33.
Since I didn't have access to every scope that I was interested in, often while I was killing time watching a game on tv, I would use the schematics posted on various vendor websites to draft out a cardboard template of a scope with the min/max eye relief written on the rear objective. Then I could hold it up to a mounted scope I knew worked well to make an educated assessment of how well a particular model would work for me. It was surprising how some scopes that looked promising based on published specifications got rejected because the location of the turrets or front bell prevented the scope from being moved rearward enough.
I know I've said it before, but I love the template idea you have there. When scoping a rifle, I am pretty critical myself, in regards to eye relief. And aesthetics. I also take into consideration what the rifle is going to be used for. Mine is just a range toy, so it gets scoped accordingly:
I know, the Zeiss that's on my rifle is a little big, but it works great for what I use it for. It has the Z6 (600 yard reticle). I use it out to 500 yards, when I shoot it:
I know, some guys don't like the size of the scope, but I'd rather run that, than use extended rings. Those are tacky as hell.. Besides, I generally hunt with a 3-9x40 rifle scope anyways..
I've been pretty happy with how this one shoots. I was a little worried when I first bought it, because I heard all the horror stories about these being inaccurate. Luckily this one has shot sub moa, far more than it hasn't. Good enough for the girls I go with.