Thanks for the reply George,
#1 - Neither of my base plates are warped "all that bad" and I do think I can squish it flat working from the middle out, and using an impact to bolt it down. I was just curious, since they both are identical including the minor warp.
#2 - Yes, I am going to have to grind down the insides some because it takes a punch and hammer to remove the pins now. But, I will also try your other ideas like using emory on the pins some too.
#3 - That's what I wanted to hear about your added holes and I don't think I'll need them; but while the thumb is at the fabricators I'll probably have them added anyway, just for an in case situation.
And for #4, that was my original main intention for the thumb. To use with my forks for my annual limb cleaning around my small property. Making 1 or 2 trips hauling brush vice my current many, many trips. I just thought why not get another base plate and be able to use it on either. But, after seeing just how heavy it actually is - I'll probably end up leaving it on the forks for the most part.
George, have you experienced any problems with the thumb pins getting rusted at all? That's another item my fabricator brought to my attention -- there are "no" grease fittings at the pin holes [like on every other backhoe or grapple I've looked at] and they are a swivel item? I'm debating whether it would be wise to drill, tap, and install grease fitting also?
dfkrug, Thank you for the useful suggestion and that will be a viable resort if needed. But, since I'd have to cut and grind anyway with steel rod I might as well just get the longer pins from TSC (local shop, about 2 miles away) and cut them short enough to fit and drill a keeper hole in.