There is no need to change the bolt face on a Mod-7 with .308 -ect bolt face. I just checked both my 7-08 and .260 with a .35Rem case. Though they wouldn't chamber it, (bolt close), they did feed and extract/eject the case.
However, I would chamber it for .358 (Have both a .35Rem AND a .358). I also would NOT re-bore a factory Remington barrel. E.R. Shaw will rebarrel to factory contour, and even their barrels are better than the factory offerings. Or, have a gunsmith turn down a Shilen or such.
Any velocity level you want up to approaching the .350RemMag/.35Whelen is doable with the .358. It's simply the .35Rem on "steroids". There really isn't as much difference between the .35Rem and .358 as you would imagine. Both run out of powder space before you get drastically over pressure with appropriate powders. (ie: Acc.#2520, IMR3031).
The .358 only holds about 3.0gr more powder and the .35Rem can be run to within ~5,000psi of the .358 with reloads. Hence, the difference between my .35Rem handloads and the .358 is the difference between 2,250fps and 2,500fps. This is with a Marlin M336 and a Browning BLR. (200gr bullets).
The best thing about the .358 is the abundance of .308 cases to reform for reloading.
Given the cost of .35cal bullets, I would just get a Rem. Mod-7 in 7mm08 (or .308) and call it good..... I really, really like my 7mm08. Even more after spending a year loading, shooting, and hunting with a .260Rem in a Rem. Mod-7.....
If wanting a lever-action, go with a Marlin .338ME. Greater powder capacity (slightly), and better down range ballitics. (But has same short range "smack" on deer as the slightly larger .35cal bullets.). I prefer my .338ME to my .358BLR due to ergonomics, as well as ballistics.....