the PT can only be modded so far, if your going for accuracy you buy the PT and take the best parts to use on an MBK, like the datewheel, the bezel insert is good enough on the PT to be reused IMO, the PT spring bars, bracelet since the MBK isnt that much better than PTs bracelet, and of course the 2846. this is what i would do if i were serious about a 1665 rep. its still relatively cheap and no where near NDT/yuki prices.
my 5513 im slowly building will probably cost me about $1200 when all is said and done.
so far i have an mbk 5513 case
mbk bracelet
GEN dial
GEN T19
GEN insert
GEN crown, tube
2846
WO pinbars
clarks hands
but i still need to get the movement serviced by the zig'
lug holes done and tube replaced, and im trying to find some GEN 580 endlinks
im probably about $400 away, 5 years ago i could have bought a used gen 80s 5513 for only $1000 more.
1665 parts cost significantly more if youre going all gen.