Boy, do I have some tales regarding older and now bearing (and effin split PLINTH!!!) knackered LP12s coming up all over eBay UK. Current model has sorted most issues but at what cost when a Technics can be had for a fraction of the price!
Good luck with the arm change, but unless you have another mounting board, can the Micro Seiki arm go on without carving the original up? Wrong thread, but take great care with exit cable dressing and ensure the suspension bounces evenly as well as having good lateral movement side to side and back and forth with no binding...
I'll put my Linn set-up 'chip' back in its box now... Gawd, you can take me away from this stuff, but it still lives inside ready to clog up threads when this is about nice looking tirntables...