gauges Pressure feet of water

I have a selection of "delivery of pressure in feet of water" gauges by;
Frank Pearn & co Ltd, West Corton, Manchester.
Budenberg, Broadheath Manchester.
Sulzer Bros (london) ltd. Leeds.
Harland engineering Co. Ltd, Alloa, Scotland.
They all have some age, with a outer brass casement and the three Frank Pearn gauges are attached to a
triangular mohogany mount.
Could anyone advise me if they are of any value please?

Howdy Squire - defo maybe perhaps we could - but a few pics would help narrow the valuation

Sulzer are still going very strong and judging by the type of gauge I am thinking there would of been many applications where these were used in the pumping world - agriculture - industry - domestic etc. So a limited niche market as to todays buyers would be open to you as there are software applications that do there job these days but for the collector the condition would be everything - as for value - how much would I want to pay for such an item - from £20 upwards - and if I was bidding against someone who knows where it could go - send some pics so we can see detail - perhaps engine collectors with pump displays would like them for authenticity!

best

Hamish

Thanks for the reply Hamish, will try to post some pics very soon