The generic "Excel" label was used by the B. Elliott Machinery Group (Victoria, Cardiff, Progress, Invicta and others) to market lathes, millers, small jig borers, precision filing & sawing machines, tool & cutter and surface grinders & other machine tools from the 1930s until the 1960s; the Excel name indicated that the various products would be of better-than-average quality and usually directed towards a specialised segment of the market. 
The Excel No. 1 jig borer was a straightforward copy of the American Liney Jig borer and, like all others of its kind, used a fixed compound table and relied for all vertical movements on a quill-feed head that ran on ways machined on the inner face of a heavy cast-iron column. The head, of massive proportions for its capacity, was counterbalanced by a weight hanging from a roller chain inside the column. The only way of moving the head through its 8 inches of travel was by hand,  there being no rack or gear feed - however, with great ingenuity, the American designers did not just allow the weight to balance the head but arranged for the chain to lift in the middle of a flat bar that connected to both the main casting and the quill - so counterbalancing the latter and helping to reducing backlash.
A 0.5 h.p. 1425 rpm motor was fastened to the back of the column and drove forwards via a ball-bearing supported and adjustable intermediate pulley to the main head by V belts giving eight speeds of: 225, 350, 475, 740, 1000, 1700, 2000 and 3400 rpm.  The drive was enclosed by a front-hinged guard, stayed by a two-part tie bar, that neatly and safely covered all three pulleys.
The quill travel was 3-inches and the distance from its centre to the column ways (the throat) 5.75-inches. The spindle assembly - beautifully made in nickel-chrome steel - was heat treated, ground all over, lapped on its bearing surfaces and help in high-precision bearings that were claimed to need no adjustment in service and which were provided with fifty pounds of pre-load pressure. To obtain perfect concentricity the outer diameter of the quill and the spindle nose were finish ground whilst running in their own bearings - and to prevent the spindle suffering interference from pull by the drive belt, its pulley (mirroring the arrangement used on many high-class lathes) ran on an independent set of ball races.
Collets were held in the quill by a compression nut on the nose - and could be had in sizes from 1/8" to 1/2" in increments of 1/32". Unfortunately these collets were of the ordinary split-from-one-end type and so limited the machine's usefulness as a light-duty vertical miller, the sideways forces on the cutters causing them to work loose unless only the most judicious of cuts was taken. In recognition of the fact that so tempting a small machine would (unless locked in a strong room) be pressed into service as a vertical miller the Linley company went on to equip their version with Schaublin Type ESX collets which, being split from both ends had a vastly-superior gripping ability. In a similar vein the much later British Downham version of the machine could be had quipped with an alternative collet set into which milling cutters could be screwed. If you have one of these machines and wish to mill with it contact Crawford Collets to see if they can supply from stock the correct collets - possibly listed as Brown & Sharpe 00 or 00A, catalogue numbers 4996 and 5071.
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