Assuming standard gauge. Whilst I haven't a drawing to give you don't forget that if you can get hold of any drawing on paper in any scale and have access to a scanner you can adjust the scale of the scan and reprint. Reason I say that is your local public library may have some modelling books with 4mm scale plans you could borrow to scan.
also suggest looking through other pages on that website.
otherwise search on google images , its amazing what turns up, and is a lot easier than searching standard google
Simon Dawson (Simon D.), Narrow gauge Francophile interested in 1m, 60cm,50cm , 40cm and smaller gauges . Build in scales from 1/6th to 1/24th. Also 1/32nd and 1/35th using 16.5mm track to represent 50cm and 60cm gauges. http://www.rue-d-etropal.com
the drawings linked to above could be rescaled from measuring the wheelbase - 10ft or so, if you resize it, and the gauge isn't right, then try again, but trying to rescale to 4'8.5" is a pain, better to have a round number to measure.
Re scaling - Assuming you have a graphics package I suggested adjusting the scan as it is extremely simple. You only need a calculator and Photoshop (or similar) then adjust the number of points in the output image size. Effectively you convert the dimensions to full size by multiplying up then divide down to get the new scale ratio. The easy bit is that by using the scan size not the actual engineering drawing elements it doesn't matter what units the thing is drawn in.
Example a 4mm drawing to start with is 1:76 input with output required at 1:32.
1) Scan with at least 600 dpi set so that you will have enough grabbed pixels to still give you enough pixels for a decent quality print out when you spread them out for printing.
2) In your graphics package open resize image and look at the scanned image size for the width in points. (For an A4 page scanned at 600 dpi that is 297.6 points)
3) Multiply by 76 to convert to full size then divide by 32 to give the output size required at the new scale i.e. 297.6 x 76 = 22617.6 points and then 22617.6/32 = 706.8 points. If you wanted O gauge either UK or US simply substitute 32 with your choice of 43 or 48 and for G 24 for 32.
4) In Photoshop with resample image unchecked now simply type the required number of points for the output into the width box. The dpi will change and resize the image to the new scale. In the case above to 252.6dpi, more than adequate for the new drawing to print out acceptably.
5) The new rescaled drawing would fit on an A3 printer.
Hope this helps. I find it much easier doing it that way than trying to work out % multiplications on a photocopier as you only have to bother with adjusting one linear length.