No...They cannot. The knife has to be ordered with that option.
Best, Capt. Chris

Capt in your opinion what benefits does the model 6 grind add to a blade? i.e. easier sharpening?

A Model #7 is "named" The "Fisherman-Hunter". It certainly lives up to that name..."BUT"...(There comes that word again) the #6 grind makes the knife far better suited for the "fish" side of the name. You can lay the blade down (flatter) and skin fish easier, faster and closer.
It also works better in the kitchen. That's why a Model #6-4 1/2", "Steak" knife is so named and chosen by the Randall shop to accompany the #6-9", Carving set. In short, at least for "me", ordering your Model #7-4 1/2" or 5" with a #6 grind just makes more sense...for it's "intended" purpose.
If you are looking for more of an "all-around" knife (I'm not ever sure what that means) then the standard grind "Fisherman'Hunter" might be the better choice. It has a little more "backbone" and is the perfect companion to it's big brother, The Model #3! Hope this "sorta" answers your question.
Best, Capt. Chris

Ever seen a #3 with a #6 grind??

Mike,
Yes I have. Although they are not available at the present time, the Randall shop made them in the past. I don't know the exact amount, but it was certainly more than just one forging and went on for a period of time.
Best, Capt. Chris

Here's an early one (Sheath is a bit older then the knife):



Best,

Great knife Ron, How much time diff. in sheath and knife?

Thanks, Bernie. I own just the sheath and not the knife. The sheath is mid '46 or earlier. The knife could be as much as 10 years later. With the No. 6 grind the ability to narrow it down by whether or not it has a "blade flat" goes away.

Best,

Here's a nice Model 3 with the Model 6 grind from the early to mid 60's...

Perry-

That's a great looking knife and a real "user" IMHO. Thanks for posting.