I just picked up an Enfield 1917 that has a weaver base forward of the action and two tapped holes for the rear base. My question is any chance the distance between the holes are standeredized? Meaning can I buy weaver bases for a 1917 and they will fit? It is an Eddystone. Thanks, Optik1

The military Enfields did not come drilled and tapped for scope bases so any that have been will be 'custom'. The rear and front bases don't usually end up being the same heights, depends on what the rear action profile ends up being after the rabbit ears are cut, ground, milled or otherwise butchered off and the rear sight recess filled.
It seems this work has already been done to your Enfield but there are no off the shelf bases, just have to mix and match to find something that will fit. The fact your Enfield is drilled and tapped for a rear base but has none probably indicates the previous owner had trouble finding a suitable mate to the front Weaver base.

Damn, just what I feared. Can a good gun smith determine how level or unlevel my gun is? Thanks, Optik1

A good gun smith can do that and shouldn't cost too much, but Id choose to get the bases on the action as opposed to on the barrel.

Rem mod ? was an Enfield and Weaver made a set for them..Winchester also..Sorry I can't recall the base number or the model number...I have a set someplace if one of these guys can't come up with that info.