What is the weight of the Series 1 MK II?
I'm not actually sure, but I've got a manual for it somewhere, I'll try to dig it out this week. The chap who brought it to me brought it on his 7.5t lorry, so all I can be sure of is it weighs less than 3.5 metric tons! I'd be surprised if it was much over 1 metric ton though. The DC motor is quite a lot heavier than the regular motor, but can (just!) be lifted by one person, not that I'd like to try fitting it without a crane... the knee & column of the Mk2 are heavier than the manual Bridgeport; the table is shorter & wider, so probably about the same weight overall, especially if your manual has power feeds.
IME, £1600 will buy you a rough but - more or less - working machine; I've had 2, the first one had a bad bearing in the fan that cools the DC motor, and the mist/flood coolant didn't work, also it had the TNC150 controller. The second one, everything works bar the mist coolant (which I don't think is fitted, there's nowhere for the air supply to go), I did have a servo motor go bad which cost several £ in fuses before I figured it out. I got very lucky with mine, the guy selling it on eBay had it finishing at about 2.30am on a Tuesday... so I stayed up to finish the auction... had he finished it at 5pm on a Sunday it'd have gone for at least £1k more.
As far as I am aware, there are 4 variants of the TNC151 controller: A, B, P and Q. I've yet to determine what - if any - differences there are between them. I'm not even sure which one I've got... As far as I know, all of the '151s will accept drip-fed programs. You need a piece of software (readily available from Heidenhain's website) which interfaces between a PC with a serial port & the machine. I run mine on an ancient & nearly dead laptop running Windows XP. The front panel of the machine will tell you (broadly) which controller you have (i.e. 150, 151 or 155), IIRC the 2500 has a different shaped control cabinet (more like a console than a flat panel). I could never get mine to work properly with G-codes. so I just use "Heidenhain Conversational". I use CamBam as my CAM software, someone else had written a TNC155 post-processor which I hacked extensively to work with the TNC151. There's still some bugs in it, but it works OK for my purposes.