The "original" 4513TSW with the cutaway grip profile (to allow the use of the shortened 6-rd magazine) was made for a couple of years, at the same time of the original 3913TSW that used the same cutaway grip profile design.
I picked one up back then and used it for several years, until they issued me a new production 4513TSW with the standard grip profile (which allows use of the standard 7-rd magazine, such as that used on the 4516 & 457 series). I still have mine, but why keeping running all those rounds through mine when I had an issued new-production 4513TSW to subject to all that wear & tear?
The original 4513TSW also lacks a few features of the newer production models, such as the loaded chamber visual inspection port; the slide being machined to accept the spring-loaded, decock-only assembly; and the accessory rail. The newer slides no longer require the downward angled machined slot for the removal of the right side ambi lever, either (for slide disassembly), and they've made some slight revisions to the machining inside the slide.
The 6-rd magazines made for the original 4513 differ from the 6-rd magazines made for the CS45, BTW. They lack the additional impressed dimples needed on the CS45 mag bodies to help prevent displacement of the top round (caused by the sharper recoil of the lighter, faster cycling CS45).
The wide & flat butt plates for the original 4513 can still come on magazines ordered, but last time I called they weren't available as separate spare parts. The curved butt plates will work on the mags, though.
I modified a set of Hogue grips for the standard 4516/457 to fit my own original 4513TSW (and one belonging to a friend), but it was a bit of a pain.
This is my own original 4513TSW (top) and a new production 4513TSW (bottom).
This is my 4513 pictured next to my CS45. I have a magazine with the curved butt plate in the 4513 in this image.