Restoring My New to Me 404

I can do something over the summer or if we have a couple of warm days that are out of place. I was thinking high temp silicone would be flexible and last longer though I have both. Is there a specific location for the welds that can be reached through ash pan door when cold so no completer take apart? I do have to say at 1/8 open on primaries and 0.035 to 0.04 draft the stove at a constant 400 and quite appropriate for current weather of 45 degrees outside and no wind. The fire box about broke this old back installing as very hard to hold on to.

Added a draft regulator and a completely different stove. With baro damper set to .02 above the damper it is 0.04 below it and will easily cruise along at 425-450 and does not look like a blast furnace as it did without the baro damper and in both cases MPG D 95% closed.