I’m in my early 60’s, way to fat, have an average length 7” member, and on the surface don’t look like the most satisfying for a young lady.  

oh Shit.  

... at least, not if  you measure properly.  But it's not ridiculous.  
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Lots of braggarts measure underneath, or whatever, to claim 9" or 13" or whatever number they need to satisfy their insecurities among the other insecure braggarts.  But they're easily ignored.

Average erect in the USA is somewhere around 5.5"    There have been numerous studies and they never quite come up with the same answer.  But in general, around 5.5".  

I’ve been measured by a few different woman, base of the shaft at the ball sack.   All got me right at 7”, I just thought that’s pretty avg.  plus I’m a grower, not been blessed with the oversized girth and length.  

Typical measure is "bone pressed" on the top side of the penis shaft.

What's the difficulty? Build a contraption with a hole in a wall.  Behind that is a compressible layer. Start banging with your -----> and see what the max penetration is.  Guys who measure from the tip to their belly button or anus will be out of luck with this fool-proof device.  

Ok.  Wouldn’t that make me measure larger?  I’m also pleased with the amount of cum I get per load.  1st is a lot, 2nd smaller but good 3rd, when it happens very small amount but still pleasing.

...then start with the tab at the base on the top, wrap around and find the base underneath.

It sounds like you were measured for girth rather than length.  

From pubic bone along top of penis straight to the tip is correct.  
Any measure along the underside is fake -- that's how the braggarts get their fish stories.

Take a box, maybe a tissue box, around 4" x 4" on one end and around 12" long (or some other long box like that: shoe box?).  Cut a small hole (approximately equal to your girth) on one of the 4" x 4" sides and cover the hole with a piece of masking tape. Make some Jello and fill the box with liquid Jello and let it set in the fridge for several hours.  
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Peel off the masking tape. Without breaking the box, get your schlong up and jam your jammer into the hole, displacing Jello gel which will seep out the front or other weak spots on the box. (Line the box with a plastic bag or aluminum foil layer, if your first attempt is too leaky.)  Ram it in a few times WITHOUT breaking the 4" x 4" side with the hole.  
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Remove your Jello-covered jammer. Cut the box in half along the long axis to expose the crater left by your schlong.  Measure the depth of the crater.  Just to repeat, remove your schlong BEFORE cutting the box in half along the long axis.  
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The DEPTH of the crater made with your maximized schlong is its USEFUL length. No cheating by adding a couple of inches topside up your stomach to your belly button. No cheating downside be measuring all the way to your asshole.

...or just get a block of ballistics gel.

Give you a medal. You deserve it.

Remember, most girls have a G-Spot in the forward wall of their twat. So if your wang curves upward it will be stroking her there perfectly in mish or CG.
It's an ill wind that doesn't blow someone some good.

You may be surprised that she doesn't care what size your penis is.  I always appreciate a good tongue!  ~K~

So yes you are probably "normal"  

but most girls don't mind it that thick     LOL

I believe its all in the technique.  7" is a pretty nice size if you ask me. If you can play with my tities the right way and stimulate me I would love to get on top on that 7" and ride while you pay special attention to my titties. I can see myself getting amazingly wet and achieving a stiff clit and having an amazing orgasm. Like I said its all in the technique and where your mind goes while your doing the do Ive had some of the BEST orgasm with my ATF guy and hes no bigger than 3" erected. But his foreplay is amazing. So by the time I get to penetration it feels like 9"

Wait, so your telling me all those oversized dicks in porn arent necessary, huh ...who knew ...LOL

I think a 7 incher would be perfect. As it is, I have 8 (if the girl is super hot and I’m really horny it’s 9) and most girls who “deep throat” can’t take it all. It’s a real joy to find the rare gems who can.  

Oh no.  I’ve got a pencil dick, long and skinny.  😢