Old Obliterators for Jokaero?

I have been debating on this for about a week now. I have some of the old style Obliterators on a small base, and personally I like them as is much better than the mad monkey models the Jokaero Weaponsmith currently has. So my intention is to use these old school obliterators for Jokaero in my new Grey Knights armies.

The old ones definitely do not look like the current model, so I have been really wondering what I would do eventually with these two old models. It does seem like a logical solution.

The problem really is, should I do some converting to it, and if so, what. I have no intention of putting an orangutan head on the model, but I am open to the idea of something. So I figured while I am debating ideas on it, I would throw it out to the public. I would definitely like to do something with them, just not sure what at the moment.

There could be an opportunity here for some Mars alien or construct from the adeptus mechanicus, so I have been also looking at lore etc.

It seems that the Grey Knights are not above using aliens, and there just has to be more morphing types out there, without resorting to monkeys. The unit I am looking at would include 3 inquisitorial servitors with multi-meltas and 2 Jokaero with other misc. This gives me a unit of 5 multi-meltas firing out of a single vehicle.

What do you think of using Old Obliterators for Jokaero, good idea or no go?

What conversion work on the model if any do you think should be done?