A few comments having experience with Ruger No. 1ís, p-dogs and scopes. First, fixed magnification scopes will generally have greater eye relief than variables, an 8-10x fixed scope with a fine reticle is generally enough scope for p dogs at the range you are likely to get hits on (200-250 yards) assuming you are shooting tuned reloads and that you have tuned your No. 1 by bedding the barrel and have had the trigger worked on by a Ruger experienced gunsmith. Getting the barrel crowned might also assist in increased accuracy for small targets.
Try as many scopes as possible at a quality dealers location for comfortable eye relief, there are a lot of good quality optics manufacturers out there today.
I went through this tuning process to varying degrees with a standard barreled No. 1ís in 22-250, a heavy/varmint barrel 220 Swift and a light sporter in 7x57 Mauser. The reloads tuned in for the rifle and the trigger work was more helpful for consistent hits on small targets that higher mag optics. And a guy with an old Sako Forester in 222 Rem with a fixed 6x Leupold regularly out shot me and I had higher mag optics. Learning experience about custom reloads and other variables.
And this is from a guy that also shoots a Cooper Montana Varminter in 6mmBR with a 12-40 Nightforce scope, but that is for 300+ yard benchrest games.
Good shooting and enjoy that single shot!