The drilling on the flange allows the flange to affix in only one position, that's why the orginal works, it hinges in a direction that is free inside -the only way it could be mounted.
I would think but am not sure, the manufacturer of the universal would have adhered to a standard with respect to the above so it will work wherever it is used, or otherwise convertible some how.
I second the vote on the WEMA units, no arms nor anything electrical exposed inside or outside tank. Single shaft with donut style floater riding on it, cast stainless flange and seal welded tube, very well made units.
I paid about $60 delivered, or so, per. Grady will give you the sender length, which is 3/4 inch shorter than the tank depth, be sure if you order to specify the "sender length", even though they may ask the tank depth, they do as a check.