First off, I don't think anyone is accusing you of being a liar about your weight, lifts, or LBM. I believe what others are suggesting is that your LBM estimation is simply incorrect. It's lower, beyond a shadow of a doubt.
And others are talking about your weight because you're talking about competing in a weight class-based sport, and the thing that will help you the most is losing weight. Makes sense, right? If other people see one particular thing that stands out as the thing that would help you be competitive in the sport more than any other thing, they will talk about it more than other things.
So. I'll move on. I'm going to talk about novice class first, and then SHW, which is the class you would be in if you moved past novice, at your bodyweight.
Things I've seen in the novice class: 225 lbs per hand farmers carries for 60 feet
200-225 log press for reps minute
405 deadlift for reps in a minute
250 lbs hussafel stone for max distance
200 lbs atlas stone to shoulder max reps in a minute.
I'm using those as a baseline because they have prescribed weights attached. There will always be max-lift events. I would say that for novice, you could expect a 280-300 lbs max log press to win that event, a 550- 650ish deadlift (this varies greatly), similar axle press (maybe 20 lbs less, novices suck with axle), the ability to put a 280 Atlas stone on a 4+' platform.... etc. The list goes on, but that gives you an idea.
Now let's talk about SHW class, at local shows. I've seen a 600 lbs deadlift for max reps, 800+ lbs deadlifts for a max, 350-380 lbs log press, 550 lbs front squat, 380+ atlas stone max, etc.
So here's what all this data tells me. You could actually compete in a novice comp today, and if you're not terrible at the moving events, of which there are generally 1 or 2 per comp, you would not embarrass your self. I gave you high end numbers, but I can promise you the low end numbers will be worse than yours across the board. So that's a good thing. You could do a comp this year and have a great time.
Here's my advice to you... pound your squat,deadlift, and OHP for the next year, mostly with barbells, and practice at least one moving event every single week. Let the bench press take a back seat in your training, it's just not that important outside of higher rep sets as accessory work to the OHP. Train with strongman implements often. Drop 50 lbs over the next year, in order to improve your conditioning for moving events, and likely give you better leverages for your lifts across the board.
And the most important suggestion I'm going to give you is to sign up for a show that is sooner than a year from now. Get your first show under your belt in the next 6 months. Get over that mental hurdle and gain the experience. It will get you psyched up for future events, it will give you SPECIFIC things to train for, and it will reveal your weaknesses better than just training without preparing for a show would do.
Best of luck bud, I hope we get to hear from you a lot more. Not enough strongmen on this site!!