Max tongue weight to tow with '76 D26-RT?

[Mosin]

Hi All,

We're considering towing a utility trailer behind Pandora ('76 D26-RT) to summer festivals and desert camping to eliminate the clutter and pain of loading and unloading bikes, shelters, propane tanks, water, etc inside the rig and on the roof. Until we decide what type/size utility trailer is best for us we're going to rent from Uhaul. Probably a single axle 5x9 utility trailer with ramp to start. While the tongue weight won't be anything near what I guesstimate a boat or travel trailer would be, after reading some archived posts here regarding rear frame extension failure (which could potentially end Pandora's glorious life, and certainly endanger ours) I'm wondering if 300lb. tongue weight is the maximum Pandora can take, and if so, if I should shoot for 250lbs or under to leave a safety margin. If the tongue weight is supposed to be ~10% of the total GTW I don't suspect we will even come close to 300lbs, as the Maximum Load of 1650 lbs (for a total of 2890 lbs. Maximum Gross Weight) for the 5x9 utility trailer is far more than we anticipate ever trying to lug behind us. Still, I always play it safe with Pandora, so I'd like to get a ballpark maximum tongue weight in mind to plan around. TIA for any responses!