Welcome to our group, Timothy.

Many members of the Douglas family have Indian connections, and I would welcome further research into those families.

Timothy, I put Clayslap+Douglas into Google, and got several results.

I put Clayslaps+Douglas+slater in and found this in 1824: 

Douglas, A. shoemaker, 8, New street, Calton   
Douglas, D. silk and cotton dyer, 46, High street   
Douglas, Edward, slater, Clayslap, near Kelvin bank   
Douglas, George, reedmaker, 94, Candleriggs   
Douglas, Geo. lead merchant and plumber, 591, Argyll st.   
Douglas, Hugh, merchant, 21, Carlton place   
Douglas, J. T. and A. & Co. merchants, 31, Miller street   
Douglas, J. slater, 45, St. Ninian street   
Douglas, James, slater, 21, New wynd   
Douglas, Jas. & Co. joiners, 22, Montrose street   
Douglas, John, writer, 32, Hutcheson street   
Douglas, J. milliuei', 631, Argyll street   
Douglas, J. C. writer, factor for Blythswood, 52; house,   10, Miller street   
Douglas, T. D. insurance broker. Tontine back buildings ;   house, 1, Blythswood place   
Douglas, Peter, vintner, Woodlane, Broomielaw   
Douglas, Thos. grahi merc'a. Douglas court, Grahamston  
Douglas, W. & P. spirit & porter cellar, 17, Laigh kirk cl.

Thanks to Sally for the following:

Watercolour of Old Wynd looking to Trongate from an album of 37 watercolours of Old Glasgow, Partick and Paisley by William Reid Mainds (fl. 1885-93). The Old Wynd linked the Trongate with the Bridgegate. The Old Wynd and New Wynd were laid out in 1573 to link the Trongate with the Bridgegate. In the 19th century the City Improvement Trust created Osborne Street which cut across both, and the railway obliterated the southern part. William Reid Mainds' watercolour is a rare illustration of one of the old roads going south from the Trongate,and shows the typical range of range of buildings which could be found there.

Caption title: Old Wynd looking to Trongate.

http://special.lib.gla.ac.uk/manuscripts/search/detail_i.cfm?ID=287