These sites show the general idea for plugs:
https://www.grdiesel.com/store/fuel-...k-connect-plug
and
http://www.advancedfluidsolutions.co...pes-3527-p.asp
Unfortunately they are probably not exactly the right size and there's a risk of damaging the 'o' rings in the female connectors if they are tight or have sharp edges.
The fuel connector spigots are size 10mm inlet to the filter and 12mm outlet to the fuel delivery line.
The actual spigot sizes are 9.9mm and 11.8mm as I measured. So those are the required plug sizes.
Not being able to find them for sale I turned a pair out of acetal plastic.
Maybe possible to change the filter without plugging the lines but I like having it under some control...
A small engineering firm might turn aluminium plugs, acetal if you can get it, or nylon. Ad hoc methods like screwed up glad wrap are not likely to work well, might dissolve into goo and increase the probability of dirt getting in, not so bad on the supply side but the delivery side not so good.
Of course it would be more sensible just to get it done at a Ford dealer, but where's the fun in that?