Welcome to the forum!
The T60 that you have (1952-A45) has the following stock configuration:
ThinkPad T60 (1952-A45)
Based on 1952-43U: T2400(1.83GHz), 1GB RAM, 60GB 5400rpm HD, 14.1in 1024x768 LCD, Intel 950, CDRW/DVD, Intel 802.11abg wireless, Modem, 1Gb Ethernet, UltraNav, Secure chip, 6c Li-Ion batt, WinXP Pro
... which means that it is a 4:3 model. As you may (or may not?) know, both T60/p's and T61/p's came as 4:3 and as widescreen 16:10 models; see e.g. the
ThinkPad Notebooks; 2005 to present (withdrawn models) for a list of various models.
You say that you want to make a "FrankenPad" but there is no standard definition of what a "FrankenPad" is, and therefore I suggest that you specify in more detail exactly what you want to do/achieve (and why?). Anyway, I assume that you
might want to put a motherboard from a (4:3) T61/p in your (4:3) T60 frame.
If this is indeed the case, I kindly suggest you search this forum for more information about this topic, since it has already been discussed
extensively and therefore is described in much detail - so a little searching will most likely reveal all you want to know. See e.g. the thread
YAFP (Yet Another FrankenPad) project (T60p/T61) and all the references (threads) mentioned therein, incl.
T60/T61 hybrid parts selection question) (and the links pointed to therein!) and the thread
Parts for the ultimate 15” T60 UXGA FlexView w/T61(p) mobo?) as they contain much useful information, which you then need not ask about...
The 42W7866 motherboard that you have found is for a widescreen T61 - see e.g the thread
T61 with dead GPU want to replace mobo or see
System service parts - ThinkPad R61, R61i, and T61 (14.1-inch widescreen) and will
not fit in your 4:3 (non-widescreen!) T60.
Always remember: Google is your friend!
If you wish to keep your T60, but would want it to be faster, then I am
convinced that you would get by far most "bang-for-the-buck" by simply upgrading it to a SSD.
Johan