It depends what you're going to do with your Tikka.
If you're selling it, keep the scope and mount it on the M70. If you're keeping the Tikka, buy a scope for the M70 to accommodate the type of hunting you expect to do including distance, size of target, etc.
Please remember that if you are a typical hunter that most of the time you will have your scope set at a magnification of 3 to 4 and very seldom at maximum magnification.
Also keep in mind that large objectives are designed for particular applications and not necessarily to gather more light (highly debatable subject).
I would go for the lightest weight and smallest magnification that will do the job for you and not larger than 40mm with a maximum magnification of of 9 or less.
If you insist on a 3-9, I would look at the
Nikon Coyote Special 3-9x40 - Mossy Oak with BDC reticle and special anti-glare design at the front lens
and available for less than $400, if you can find one.
You could also use a Nikon 2-8x32 with BDC reticle or something like that. The Nikon one claims a 95% light transmission, and that is just as high as their 50mm scopes.
And, if you're a fan of Leupold scopes, look at their 2-7x33, etc.
I find that maximum magnification gives me the impression and feeling that you are not holding the gun steady enough and this will tend to affect your shooting skills.
My 2 cents,
Duke1