Upload & Sell: On
I swapped from my long-term Canon system to Nikon about 4 years ago but I was using an adapted Canon FD200/4 Macro (which is very sharp) on my Nikons, until I bought a used Micro-Nikkor 105/2.8D lens. It too is very sharp, but others decided to keep it even after the new VR version was produced, so you may want to check those opinions/results. I used my 'D' for weddings (rings, shoes, cropped head, hand and dress details) but I didn't like the fussy background, so I tried a used older 105mm/4 AIs with it's PN-11 which I prefer, which is an opinion rather than a test. There's also been a bit of discussion on DPReview about the PC-Micro 85mm/2.8D and the newer PC-E version, but there's a couple of issues with size, weight and money but I had used a Canon TS-E 90/2.8 for my macro lens for a fair while! Over to you. Cheers,
p.s I suggest and try your reversed 50/1.8 on your 105/2.5, using a double 52mm male-male filter thread adapter. It's cheap and interesting, as long as the magnification works for you.